"make known by open declaration, publish, announce" (a decree, news, etc.), 1520s, from Latin promulgatus, past participle of promulgare "make publicly known, propose openly, publish," probably from pro "forth" (see pro-) + mulgere "to milk" (see milk (n.)), used metaphorically for "cause to emerge." In that case the word is "a picturesque farmers' term used originally of squeezing the milk from the udder" [L.R. Palmer, "The Latin Language"]. Related: Promulgated; promulgating. The earlier verb in English was promulge (late 15c.).

"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).

"to order or promulgate with authority," late 14c., decreen, from decree (n.). Related: Decreed; decreeing.

"make known by public announcement, promulgate," especially by herald or crier, late 14c., proclamen, from Latin proclamare "cry or call out," from pro "forth" (from PIE root *per- (1) "forward") + clamare "to cry out" (from PIE root *kele- (2) "to shout"). Spelling altered by influence of claim. Related: Proclaimed; proclaiming; proclaimer.