a priori

[ ey prahy-awr-ahy, -ohr-ahy, ey pree-awr-ee, -ohr-ee, ah pree-awr-ee, -ohr-ee ]
/ ˌeɪ praɪˈɔr aɪ, -ˈoʊr aɪ, ˌeɪ priˈɔr i, -ˈoʊr i, ˌɑ priˈɔr i, -ˈoʊr i /


from a general law to a particular instance; valid independently of observation.Compare a posteriori(def 1).
existing in the mind prior to and independent of experience, as a faculty or character trait.Compare a posteriori(def 2).
not based on prior study or examination; nonanalytic: an a priori judgment.

Origin of a priori

1645–55; < Latin: literally, from the one before. See a-4, prior1
Related formsa·pri·or·i·ty [ey-prahy-awr-i-tee, -or-] /ˌeɪ praɪˈɔr ɪ ti, -ˈɒr-/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for a priori

British Dictionary definitions for a priori

a priori

/ (eɪ praɪˈɔːraɪ, ɑː prɪˈɔːrɪ) /


logic relating to or involving deductive reasoning from a general principle to the expected facts or effects
logic known to be true independently of or in advance of experience of the subject matter; requiring no evidence for its validation or support
Derived Formsapriority (ˌeɪpraɪˈɒrɪtɪ), noun

Word Origin for a priori

C18: from Latin, literally: from the previous (that is, from cause to effect)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for a priori

a priori

1710, "from cause to effect" (a logical term, in reference to reasoning), Latin, literally "from what comes first," from priori, ablative of prior "first" (see prior (adj.)). Used loosely for "in accordance with previous knowledge" (1834).

Online Etymology Dictionary, © 2010 Douglas Harper