Forthcoming
wiktionary
The adjective is derived from forth(“forwards”) + coming(“approaching (adjective)”); [1] or from Middle English forth commyng, *forthcominge, present participle of forth-comen(“to come forth; to appear, issue”), from Old English forþcuman, forþ-cuman(“to come forth, come forward”) (present participle *forþcumende), [2] from forþ-(“forth; forward”) (ultimately from Proto-Indo-European *per-(“before, in front; first”)) + cuman(“to come”) (ultimately from Proto-Indo-European *gʷem-(“to step”)). Compare Dutch voortkomend(“coming forth, originating from (verb)”), German fortkommend(“getting away; progressing (verb)”).
The noun is derived from forth(“forwards”) + coming(“arrival”). [3]
From forthcome + -ing. [4]
etymonline
forthcoming (adj.)
late 15c., "about to happen or appear," present-participle adjective from Middle English forthcomen, from Old English forðcuman "to come forth, come to pass;" see forth + come (v.). Meaning "informative, responsive" is from 1835, via the notion of "in such a position or condition, as a person or a thing, that his or its presence when needed can be counted on." A once-common verb formation; English also had forthbring, forthcall, forthdo, forthgo, forthpass, forthset, all now obsolete.
