late 14c., publicacioun, "the act of making publicly known, notification to the people at large," from Old French publicacion (14c.) and directly from Latin publicationem (nominative publicatio) "a making public; an adjudging to the public treasury," noun of action from past-participle stem of publicare "make public," from publicus (see public (adj.)).
The meaning "the issuing of a written or printed work to the public by sale or distribution" is recorded by 1570s; as the word for the thing so issued and offered, from 1650s. Compare publicization. Parallel publishment existed alongside this word.