"one of the indeclinable parts of speech, so called from being ordinarily joined to verbs for the purpose of limiting or extending their signification, but used also to qualify adjectives and other adverbs" [Century Dictionary], late 14c., from Late Latin adverbium "adverb," literally "that which is added to a verb" (to extend or limit its meaning), from ad "to" (see ad-) + verbum "verb, word" (from PIE root *were- (3) "to speak;" see verb). Coined by Flavius Sosipater Charisius as a translation of Greek epirrhema "adverb," from epi- "upon, on" + rhema "verb."

early 14c., rethorike, "the art of eloquence and persuasiveness in language, the art of using language to influence others," from Old French retorike, rethorique (Modern French rhétorique) and directly from Latin rhetorice, from Greek rhētorikētekhnē  "art of an orator," from rhētōr (genitive rhētoros) "speaker, master speaker, orator; artist of discourse; teacher of rhetoric," especially (in the Attic official language), "orator in public." This is related to rhesis "speech," rhema "word, phrase, verb," literally "that which is spoken" (from PIE *wre-tor-, from root *were- (3) "to speak;" see verb). Since classical times with a derogatory suggestion of "artificial oratory" as opposed to what is natural or unaffected, "ostentatious declamation."

c. 1300, in boke of Prouerbyys, the Old Testament work, from Old French proverbe (12c.) and directly from Latin proverbium "a common saying, old adage, maxim," literally "words put forward," from pro "forth" (from PIE root *per- (1) "forward") + verbum "word" (see verb). Hence, in the Scriptural sense, "an enigmatical utterance; a mysterious or oracular saying that requires interpretation."

Used generally from c. 1300 in reference to native sayings, "short pithy sentence, often repeated colloquially, expressing a well-known truth or a common fact ascertained by experience or observation; a popular saying which briefly and forcibly expresses some practical precept; an adage; a wise saw: often set forth in the guise of metaphor and in the form of rime, and sometimes alliterative" [Century Dictionary].

By late 14c. as "byword, reproach, object of scorn." The Book of Proverbs in Old English was cwidboc, from cwide "speech, saying, proverb, homily," related to cwiddian "to talk, speak, say, discuss;" cwiddung "speech, saying, report."

Old English word "speech, talk, utterance, sentence, statement, news, report, word," from Proto-Germanic *wurda- (source also of Old Saxon, Old Frisian word, Dutch woord, Old High German, German wort, Old Norse orð, Gothic waurd), from PIE *were- (3) "speak, say" (see verb).

The meaning "promise" was in Old English, as was the theological sense. In the plural, the meaning "verbal altercation" (as in have words with someone) dates from mid-15c. Word-processor first recorded 1971; word-processing is from 1972; word-wrap is from 1977. A word to the wise is from Latin phrase verbum sapienti satis est "a word to the wise is enough." Word-for-word "in the exact word or terms" is late 14c. Word of mouth "spoken words, oral communication" (as distinguished from written words) is by 1550s.

It is dangerous to leave written that which is badly written. A chance word, upon paper, may destroy the world. Watch carefully and erase, while the power is still yours, I say to myself, for all that is put down, once it escapes, may rot its way into a thousand minds, the corn become a black smut, and all libraries, of necessity, be burned to the ground as a consequence. [William Carlos Williams, "Paterson"]

1550s, in grammar, of a verb, "formed to signify the desire for the action or condition denoted by the simple verb;" see desiderata + -ive. As a noun, "a desiderative verb," from 1751.

1932, noun and verb, American English, apparently imitative. The transitive sense of the verb is attested by 1940. Related: Burped; burping. Burp-gun attested from 1945.