Meaning

noun a river in southern Scotland that flows eastward to the Firth of Forth

adverb from a particular thing or place or position (`forth' is obsolete)

adverb forward in time or order or degree

originFrom Middle English forth, from Old English forþ, from Proto-West Germanic *forþ, from Proto-Germanic *furþą, from Proto-Indo-European *pŕ̥-to-, from *per-. Cognates include Dutch voort and German fort. See also ford.

Etymology from Wiktionary, CC BY-SA 3.0