1640s, "the making of distinctions, act of observing or marking a difference," from Late Latin discriminationem (nominative discriminatio), noun of action from past-participle stem of discriminare "to divide, separate" (see discriminate (v.)). Sense of "making invidious distinctions prejudicial to a class of persons" (usually based on race or color) is from 1866 in American English in the language of Reconstruction. Meaning "discernment" is from 1814.
It especially annoys me when racists are accused of 'discrimination.' The ability to discriminate is a precious facility; by judging all members of one 'race' to be the same, the racist precisely shows himself incapable of discrimination. [Christopher Hitchens, "Letters to a Young Contrarian"]
"scientific discrimination," especially in pathology, "the recognition of a disease from its symptoms," 1680s, medical Latin application of Greek diagnōsis "a discerning, distinguishing," from stem of diagignōskein "discern, distinguish," literally "to know thoroughly" or "know apart (from another)," from dia "between" (see dia-) + gignōskein "to learn, to come to know," from PIE root *gno- "to know."
Penetration, or insight, goes to the heart of a subject, reads the inmost character, etc. Discrimination marks the differences in what it finds. Discernment combines both these ideas. [Century Dictionary]
early 15c., "use of sophistry; fallacious argument intended to mislead; adulteration; an adulterated or adulterating substance," from Medieval Latin sophisticationem (nominative sophisticatio), noun of action from past-participle stem of sophisticare "adulterate, cheat quibble," from Latin sophisticus "of sophists," from Greek sophistikos "of or pertaining to a sophist," from sophistes "a wise man, master, teacher" (see sophist). Greek sophistes came to mean "one who gives intellectual instruction for pay," and at Athens, contrasted with "philosopher," it became a term of contempt.
Meaning "worldly wisdom, refinement, discrimination" is attested from 1850.
c. 1300, "opposite, contrary in position or direction, turned backward," from Old French revers "reverse, cross, opposite" (13c.) and directly from Latin reversus, past participle of revertere "turn back, turn about, come back, return" (see revert). In reference to a gear mechanism enabling a vehicle to go backward without changing the rotation of the engine, by 1875. Reverse angle (shot, etc.) in film-making is from 1934. Reverse discrimination is attested from 1962, American English. Reverse dictionary, one in which the words are arranged alphabetically by last letter to first, is by 1954.