1520s, "to impart (information, etc.); to give or transmit (a quality, feeling, etc.) to another," from Latin communicatus, past participle of communicare "to share, communicate, impart, inform," literally "to make common," related to communis "common, public, general" (see common (adj.)). Meaning "to share, transmit" (diseases, etc.) is from 1530s. Intransitive sense, of rooms, etc., "to open into each other" is from 1731. Related: Communicated; communicating.
It forms all or part of: amiss; amoeba; azimuth; common; commune; communicate; communication; communism; commute; congee; demean; emigrate; emigration; excommunicate; excommunication; immune; immutable; incommunicado; mad; mean (adj.1) "low-quality;" mew (n.2) "cage;" mews; migrate; migration; mis- (1) "bad, wrong;" mistake; Mithras; molt; Mstislav; municipal; munificent; mutable; mutant; mutate; mutation; mutatis mutandis; mutual; permeable; permeate; permutation; permute; remunerate; remuneration; transmutation; transmute; zenith.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit methati "changes, alternates, joins, meets;" Avestan mitho "perverted, false;" Hittite mutai- "be changed into;" Latin mutare "to change," meare "to go, pass," migrare "to move from one place to another," mutuus "done in exchange;" Old Church Slavonic mite "alternately;" Czech mijim "to go by, pass by," Polish mijać "avoid;" Gothic maidjan "to change."
1832, "any thing which radiates," agent noun in Latin form from radiate (v.). Originally a stove-like apparatus, as a device designed to communicate heat from steam to a room by 1855; the sense of "cooling device in an internal combustion engine" is by 1899.
"hold discourse, communicate thoughts or ideas, especially in a formal manner," 1570s, from discourse (n.). Sense of "speak or write at length" is from 1560s. Earlier in now-obsolete sense of "run or travel over" (1540s), the literal sense of the Latin verb. Related: Discoursed; discoursing.