a priori

See also: apriori and à priori

English

WOTD – 1 February 2012

Alternative forms

• apriori

Etymology

First attested in 1610. Learned borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• (Received Pronunciation) IPA^(key): /ˌɑː pɹiˈɔːɹi/, /ˌeɪ pɹaɪˈɔːɹaɪ/
• (General American) IPA^(key): /ˌɑ pɹiˈoɹi/, /ˌæ pɹiˈoɹi/, /ˌeɪ pɹiˈoɹi/, /ˌeɪ pɹaɪˈoɹaɪ/

• Audio (Southern England):

  (file)

• Rhymes: -ɔːɹi, -ɔːɹaɪ

Adjective

a priori (comparative more a priori, superlative most a priori)

2. Self-evident, intuitively obvious.
4. Presumed without analysis.
6. (logic) Based on hypothesis and theory rather than experiment or empirical evidence.

   In his opening argument, the student mentioned nothing beyond his a priori knowledge.

   • 1996, Jeet Heer, Gravitas, Autumn 1996:

     While the great critics drew their authority from the breadth of their reading, New Criterion critics often base their authority on an a priori rejection of the contemporary.

8. (linguistics, conlanging) Developed entirely from scratch, without deriving it from existing languages.
   • 2012 November 1, Laura Wright, “UT Language Creation Society invites students to learn origins of newer languages”, in The Daily Texan‎^[1], archived from the original on 26 February 2013:

     Conlangers can also create a priori languages, which have no basis in existing languages. You might be familiar with more a priori conlangs than you think: The Klingon language from the television series “Star Trek,” the Na’vi language from the movie “Avatar,” and the Dothraki language from the television series “Game of Thrones” are all examples of a priori languages.

Synonyms

• deductive

Antonyms

• a posteriori

Derived terms

• apriorism
• apriorist
• aprioristic
• apriority

Related terms

• a fortiori

Translations

logic: based on hypothesis rather than experiment

• Arabic: مُسَلَّم بِه (musallam bih), لَا يُحْتَاجُ إِثْبَاتَة إِلَى تَجْرِبَة (lā yuḥtāju ʔiṯbāta(t) ʔilā tajriba)
• Belarusian: апрыёрны (apryjórny)
• Chinese:

  Mandarin: 先驗 / 先验 (zh) (xiānyàn)

• Danish: a priori
• Finnish: apriorinen (fi), hypoteettinen (fi)
• Greek: επαγωγικός (el) (epagogikós), συμπερασματικός (el) (symperasmatikós)
• Hindi: प्रागनुभविक (prāgnubhvik), अनुभवनिरपेक्ष (anubhvanirpekṣ)
• Italian: a priori (it), teorico (it), preconcetto (it)
• Japanese: 先験的 (ja) (senkenteki), アプリオリ (ja) (apuriori)
• Korean: 선험적인 (seonheomjeogin)
• Norwegian:

  Bokmål: a priori (no)

• Polish: a priori (pl), aprioryczny (pl), apriorystyczny
• Portuguese: a priori (pt)
• Russian: априо́рный (ru) (apriórnyj), доо́пытный (ru) (doópytnyj), предположи́тельный (ru) (predpoložítelʹnyj)
• Spanish: a priori (es)
• Tagalog: matwiranin
• Turkish: apriori (tr), önsel (tr)
• Ukrainian: апріо́рний (uk) (apriórnyj)
• Vietnamese: tiên nghiệm (vi)

self-evident, intuitively obvious

• Finnish: itsestäänselvä (fi), itsestään selvä, oletusarvoinen (fi)
• Polish: a priori (pl)
• Spanish: a priori (es)

presumed without analysis

• Finnish: lähtökohtainen (fi), oletusarvoinen (fi), apriorinen (fi)
• Polish: a priori (pl)
• Spanish: a priori (es)

linguistics: developed entirely from scratch

• Finnish: fiktiivinen (fi)
• Polish: a priori (pl)
• Spanish: a priori (es)

Adverb

a priori (comparative more a priori, superlative most a priori)

2. (logic) In a way based on theoretical deduction rather than empirical observation.

   Synonym: deductively (broadly synonymous outside of philosophic arcanity)

   Antonyms: a posteriori, inductively

Translations

derived by logic

• Arabic: مُسَبَّق (musabbaq)
• Belarusian: апрыёры (apryjóry)
• Chinese:

  Mandarin: 先驗 / 先验 (zh) (xiānyàn)

• Czech: a priori (cs)
• Dutch: a priori (nl)
• Finnish: apriorisesti (fi), a priori (fi)
• French: a priori (fr)
• Galician: a priori
• Georgian: აპრიორი (aṗriori)
• German: a priori (de)
• Greek: εκ των προτέρων (el) (ek ton protéron)
• Hebrew: אפריורי (apriori)
• Hindi: पूर्वसिद्ध (pūrvasiddh)
• Italian: a priori (it)
• Japanese: アプリオリ (ja) (apuriori)
• Korean: please add this translation if you can
• Norwegian:

  Bokmål: a priori (no)

• Polish: a priori (pl), apriorycznie
• Portuguese: a priori (pt)
• Romanian: a priori (ro)
• Russian: априо́ри (ru) (aprióri), зара́нее (ru) (zaráneje), незави́симо от о́пыта (nezavísimo ot ópyta), до о́пыта (do ópyta)
• Spanish: a priori (es)
• Turkish: önsel (tr)
• Ukrainian: апріо́рі (uk) (aprióri)

Usage notes

A priori is broadly naturalized in English, but is sometimes typeset in italics.

See also

• ex ante

Finnish

Etymology

Latin a priori

Pronunciation

• IPA^(key): /ˈɑːpriˌoːriː/, [ˈɑ̝ːpriˌo̞ːriː]

Adverb

a priori

1. a priori

Further reading

• “a priori”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎^[2] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 14 May 2026

French

Alternative forms

• à priori, apriori (post-1990 spelling)

Etymology

Borrowed from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• IPA^(key): /a pʁi.jɔ.ʁi/

• Audio (France (Vosges)):

  (file)

• Audio (France (Lyon)):

  (file)

• Audio (France (Somain)):

  (file)

Adjective

a priori (invariable)

1. intuitively known, a priori

Adverb

a priori

1. (informal) at first glance

Noun

a priori m (invariable)

1. preconceived idea

Antonyms

• a posteriori

German

Etymology

Borrowed from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• IPA^(key): /a pʁiˈoːʁi/

• Audio (Germany (Berlin)):

  (file)

Adjective

a priori (indeclinable)

1. a priori

Adverb

a priori

1. a priori

Further reading

• a priori on the German Wikipedia.Wikipedia ^de

Italian

Etymology

Unadapted borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Adjective

a priori (invariable)

1. a priori

Adverb

a priori

1. a priori

   Antonym: a posteriori

Derived terms

• apriorismo
• apriorista
• aprioristico

Anagrams

• prioria, ripario

Latin

Etymology

Literally, “from the former, from that which comes before”. Introduced as a technical phrase by Scholastic philosophers, notably Albert of Saxony (14th century).

Pronunciation

• (Classical Latin) IPA^(key): [ˈaː priˈoː.riː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈaː priˈɔː.ri]

Adverb

ā priōrī (not comparable)

1. (Medieval Latin) In a manner involving reasoning from cause to effect.
2. (New Latin) In a manner involving reasoning from first principles; a priori.

Descendants

• → English: a priori
• → French: a priori
• → German: a priori
• → Italian: a priori
• → Norwegian Bokmål: a priori
• → Norwegian Nynorsk: a priori
• → Polish: a priori
• → Portuguese: a priori
• → Spanish: a priori

See also

• ā posteriōrī

Norwegian Bokmål

Etymology

PIE word
*h₂epó

Learned borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”), literally “from the former”.

The first element, ā (“from”), is a variant of ab (“from, away from”), inherited from Proto-Italic *ap (“from, away from”), from Proto-Indo-European *h₂epó (“off, away”). The second element, priōrī, is the ablative singular of prior (“earlier, former, previous”), from Proto-Italic *priōs (“earlier, previous”), from earlier *prijōs, from *pri (“before”) and *-jōs (“comparative suffix”). With *pri being from Proto-Indo-European *préy (“before”), ultimately from Proto-Indo-European *per- (“before, in front; first”).

Compare the parallel learned borrowings Danish a priori, Swedish a priori, German a priori, French a priori, Italian a priori and English a priori (“a priori”).

Pronunciation

• IPA^(key): /²a.priˈoː.rɪ/, [a.pɾɪˈôː.ɾɪ]

• Audio:

  (file)

• Rhymes: -oːrɪ
• Homophone: apriori
• Hyphenation: a‧pri‧o‧ri

Adverb

a priori

1. (philosophy, epistemology) a priori; independently of experience or empirical evidence; by reason alone

   Antonym: a posteriori

   Noen sannheter hevdes å kunne erkjennes a priori. ― Some truths are claimed to be knowable a priori.

   • 2011 December 23, Morgenbladet, page 9:

     førmoderne samfunn … hvor forskjell ennå ikke betraktes a priori som en mangel

     pre-modern societies … where difference is not yet regarded a priori as a deficiency

2. a priori; beforehand, in advance, without prior investigation or examination

   Man kan ikke a priori utelukke denne muligheten. ― One cannot rule out this possibility a priori.

   • 1894, Nils Kjær, Dagbladet:

     adskillige snes ungdom, som a priori kan henregnes til det overflødige proletariat

     several dozen young people who can a priori be counted among the superfluous proletariat

   • 2004, Thea Selliaas Thorsen, Pia Fraus:

     han [vil] ikke a priori utelukke at [sjalusien] kan være noe av årsaken til at han nå drives rundt av en uro

     he [will] not a priori rule out that [jealousy] may be part of the reason why he is now driven by a sense of unease

Derived terms

• apriori (“a priori; something existing independently of experience”)
• apriorisk (“a priori; independent of experience”)
• apriorisme (“apriorism”)

References

• “a priori” in The Bokmål Dictionary.
• “a priori” in Norwegian Academy Dictionary (NAOB).
• “a priori” in Store norske leksikon

Anagrams

• apriori

Norwegian Nynorsk

Adverb

a priori

1. (logic, philosophy) a priori; based on hypothesis rather than experiment.
2. presumed without analysis, self-evident, intuitively obvious.

Polish

Etymology

Learned borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• IPA^(key): /a‿ˈprjɔ.ri/

• Audio:

  (file)

• Rhymes: -ɔri
• Syllabification: a‿prio‧ri

Adjective

a priori (not comparable, no derived adverb)

1. (literary, logic, philosophy) a priori

   Synonyms: aprioryczny, apriorystyczny

   Antonyms: a posteriori, aposterioryczny

Adverb

a priori (not comparable)

1. (literary, logic, philosophy) a priori

   Synonym: apriorycznie

   Antonyms: a posteriori, aposteriorycznie

Derived terms

adjectives

• aprioryczny
• apriorystyczny

nouns

• apriorysta
• aprioryzm

Related terms

adverb

• apriorycznie

noun

• aprioryczność

Further reading

• “a priori”, in Wielki słownik języka polskiego‎^[3] (in Polish), Instytut Języka Polskiego PAN
• “a priori”, in Polish dictionaries at PWN‎^[4] (in Polish)

Portuguese

Etymology

Unadapted borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• (Brazil) IPA^(key): /a pɾiˈɔ.ɾi/, (faster) /a ˈpɾjɔ.ɾi/

• (Portugal) IPA^(key): /a pɾiˈɔ.ɾi/, (faster) /a ˈpɾjɔ.ɾi/

Adverb

a priori

1. (logic) a priori (derived by logic)
2. a priori (presumed without analysis)

Derived terms

• apriorismo

Further reading

• “a priori”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “a priori”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Spanish

Etymology

Learned borrowing from Medieval Latin ā priōrī (“involving reasoning from cause to effect; from first principles”, literally “from the former”).

Pronunciation

• IPA^(key): /a pɾiˈoɾi/ [a pɾiˈo.ɾi]
• Syllabification: a pri‧o‧ri

Adverb

a priori

1. beforehand

   Synonyms: previamente, antes, anteriormente

2. (logic, philosophy) a priori

Derived terms

• apriorismo
• apriorístico

Further reading

• “a priori”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025
• a priori | Diccionario de la lengua española (2001) | RAE - ASALE
• Seco, Manuel; Andrés, Olimpia; Ramos, Gabino (2023), “a priori”, in Diccionario del español actual [Dictionary of Current Spanish] (in Spanish), third digital edition, Fundación BBVA