Middle English prechen, "deliver a sermon, proclaim the Gospel," from late Old English predician, a loan word from Church Latin; reborrowed 12c. as preachen, from Old French preechier "to preach, give a sermon" (11c., Modern French précher), from Late Latin praedicare "to proclaim publicly, announce" (in Medieval Latin "to preach," source also of Spanish predicar), from Latin prae "before" (from PIE root *per- (1) "forward," hence "in front of, before") + dicare "to proclaim, to say" (from PIE root *deik- "to show," also "pronounce solemnly," and see diction). Related: Preached; preaching.
Meaning "give earnest advice, especially on moral subjects" is by 1520s. To preach to the converted is recorded from 1867 (the form preach to the choir attested from 1979).
"one authorized or appointed to discourse publicly on religious subjects," c. 1200, prechour, from Old French preecheor "preacher" (Modern French prêcheur), from Latin praedicatorem (nominative praedicator) "public praiser, eulogist," literally "proclaimer" (see preach). Slang short form preach (n.) is recorded by 1968, American English.
Proto-Indo-European root meaning "to show," also "pronounce solemnly," "also in derivatives referring to the directing of words or objects" [Watkins].
It forms all or part of: abdicate; abdication; addict; adjudge; apodictic; avenge; benediction; betoken; condition; contradict; contradiction; dedicate; deictic; deixis; dictate; diction; dictionary; dictum; digit; disk; ditto; ditty; edict; Eurydice; index; indicate; indication; indict; indiction; indictive; indite; interdict; judge; judicial; juridical; jurisdiction; malediction; malison; paradigm; policy (n.2) "written insurance agreement;" preach; predicament; predicate; predict; prejudice; revenge; soi-disant; syndic; teach; tetchy; theodicy; toe; token; valediction; vendetta; verdict; veridical; vindicate; vindication; voir dire.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dic- "point out, show;" Greek deiknynai "to show, to prove," dike "custom, usage;" Latin dicere "speak, tell, say," digitus "finger," Old High German zeigon, German zeigen "to show," Old English teon "to accuse," tæcan "to teach."
also sermonise, 1630s, "compose or deliver a sermon; preach, especially in a dogmatic or didactic style," from Medieval Latin sermonizari, from Latin sermo (see sermon). "Chiefly depreciatory" [OED]. Occasionally also transitive, "preach a sermon to" (by 1802). Earlier verb was simply sermon "preach, preach about" (Middle English sermounen, attested in late Old English, from Old French sermoner). It survived into Elizabethan times. Related: Sermonized; sermonizing.
late 14c., from Old French evangeliser "to spread or preach the Gospel," and directly from Church Latin evangelizare, from Greek euangelizesthai (see evangelist). Related: Evangelized; evangelizing.
masc. proper name, from Medieval Latin Casimirus from Polish Kazimierz, literally "proclaimer of peace," from kazać "to preach" + mir "peace" (see mir).