Middle English word forthgon comes from Proto-Indo-European *wortéyeti (To turn (transitive).), Proto-Indo-European *ǵʰeh₁-, Tocharian B come, Proto-Indo-European *prto-, Proto-Indo-European *pr̥to-

Detailed word origin of forthgon

Dictionary entry	Language	Definition
*wortéyeti	Proto-Indo-European (ine-pro)	To turn (transitive).
*ǵʰeh₁-	Proto-Indo-European (ine-pro)
come	Tocharian B (txb)
*prto-	Proto-Indo-European (ine-pro)
*pr̥to-	Proto-Indo-European (ine-pro)
*gʷm̥sḱéti	Proto-Indo-European (ine-pro)	To be walking. To come, to be coming.
*gʷémt	Proto-Indo-European (ine-pro)	To arrive. To step, to take a step.
*gʷegʷóme	Proto-Indo-European (ine-pro)	To have the feet planted, to stand steady.
*kwemaną	Proto-Germanic (gem-pro)	To come.
forþ-	Old English (ang)	Forth, forward; away; still, continuously. Onto, towards.
gān	Old English (ang)
gan	Old English (ang)	To go.
forþgān	Old English (ang)
forþgan	Old English (ang)	To go forth, proceed, go or pass by.
forthgoing	Middle English (enm)

Words with the same origin as forthgon