Proto-Indo-European root meaning "to sieve," thus "discriminate, distinguish."
It forms all or part of: ascertain; certain; concern; concert; crime; criminal; crisis; critic; criterion; decree; diacritic; discern; disconcert; discreet; discriminate; endocrine; excrement; excrete; garble; hypocrisy; incertitude; recrement; recriminate; riddle (n.2) "coarse sieve;" secret; secretary.
It is the hypothetical source of/evidence for its existence is provided by: Greek krinein "to separate, decide, judge," krinesthai "to explain;" Latin cribrum "sieve," crimen "judgment, crime," cernere "to sift, distinguish, separate;" Old Irish criathar, Old Welsh cruitr "sieve;" Middle Irish crich "border, boundary;" Old English hriddel "sieve."
1540s, "nonplus, disconcert, shut up;" 1560s, "frustrate," from blank (adj.) in some sense. The sports sense of "defeat (another team) without allowing a score" is from 1870 (blank (n.) as "a score of zero in a game or contest" is from 1867). The meaning "become blank or empty" is by 1955. Colloquial sense of "forget (something) completely, go mentally blank" is by 1990s. Related: Blanked; blanking.
"offended, angry, upset," by 1887, from the verbal phrase in the sense of "offend," attested by 1822; see put (v.) + out (adv.). Perhaps via the earlier sense of "cause to lose self-possession, disconcert" (1580s). The verbal phrase is from mid-14c. as "drive out, banish, exile;" from 1520s as "extinguish" (a fire or burning object). To put out, of a woman, "to offer oneself for sex" is attested by 1947.
c. 1200, discomfiten, "to undo in battle, defeat, overthrow," from Anglo-French descomfiter, Old French desconfire "to defeat, destroy," from des- "not" (see dis-) + confire "make, prepare, accomplish," from Latin conficere "to prepare," from com- "with" (see com-) + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put").
General sense of "defeat or overthrow the plans or purposes of" is from late 14c. Weaker sense of "disconcert" is first recorded 1520s in English, probably by confusion with discomfort. Related: Discomfited; discomfiting.
c. 1300, "to condemn, curse," also "to destroy utterly;" from Anglo-French confoundre, Old French confondre (12c.) "crush, ruin, disgrace, throw into disorder," from Latin confundere "to confuse, jumble together, bring into disorder," especially of the mind or senses, "disconcert, perplex," properly "to pour, mingle, or mix together," from assimilated form of com "together" (see con-) + fundere "to pour" (from nasalized form of PIE root *gheu- "to pour").
From mid-14c. as "to put to shame, disgrace." The figurative sense of "confuse the mind, perplex" emerged in Latin, passed into French and thence to English by late 14c. The Latin past participle confusus, meanwhile, became confused (q.v.). The meaning "treat or regard erroneously as identical" is from 1580s.