promulgate (v.)

"opaque white fluid secreted by mammary glands of female mammals, suited to the nourishment of their young," Middle English milk, from Old English meoluc (West Saxon), milc (Anglian), from Proto-Germanic *meluk- "milk" (source also of Old Norse mjolk, Old Frisian melok, Old Saxon miluk, Dutch melk, Old High German miluh, German Milch, Gothic miluks), from *melk- "to milk," from PIE root *melg- "to wipe, to rub off," also "to stroke; to milk," in reference to the hand motion involved in milking an animal. Old Church Slavonic noun meleko (Russian moloko, Czech mleko) is considered to be adopted from Germanic.

Of milk-like plant juices or saps from c. 1200. Milk chocolate (eating chocolate made with milk solids, paler and sweeter) is recorded by 1723; milk shake was used from 1889 for a variety of concoctions, but the modern version (composed of milk, flavoring, etc., mixed by shaking) is from the 1930s. Milk tooth (1727) uses the word in its figurative sense "period of infancy," attested from 17c. To cry over spilt milk (representing anything which, once misused, cannot be recovered) is first attested 1836 in writing of Canadian humorist Thomas C. Haliburton. Milk and honey is from the Old Testament phrase describing the richness of the Promised Land (Numbers xvi.13, Old English meolc and hunie). Milk of human kindness is from "Macbeth" (1605).

"publication, open declaration," c. 1600, from French promulgation (14c.), from Latin promulgationem (nominative promulgatio) "a public announcement," noun of action from past-participle stem of promulgare "make publicly known" (see promulgate).

word-forming element meaning "forward, forth, toward the front" (as in proclaim, proceed); "beforehand, in advance" (prohibit, provide); "taking care of" (procure); "in place of, on behalf of" (proconsul, pronoun); from Latin pro (adv., prep.) "on behalf of, in place of, before, for, in exchange for, just as," which also was used as a first element in compounds and had a collateral form por-.

Also in some cases from cognate Greek pro "before, in front of, sooner," which also was used in Greek as a prefix (as in problem). Both the Latin and Greek words are from PIE *pro- (source also of Sanskrit pra- "before, forward, forth;" Gothic faura "before," Old English fore "before, for, on account of," fram "forward, from;" Old Irish roar "enough"), extended form of root *per- (1) "forward," hence "in front of, before, toward, near," etc.

The common modern sense of "in favor of, favoring" (pro-independence, pro-fluoridation, pro-Soviet, etc.) was not in classical Latin and is attested in English from early 19c.