Meaning

noun the first of two or the first mentioned of two

adjective referring to the first of two things or persons mentioned (or the earlier one or ones of several)

adjective belonging to some prior time

originInherited from Middle English former, comparative of forme (“first”), from Old English forma (“first”), descended from Proto-Germanic *frumô. Parallel to prior (via Latin), as comparative form from same Proto-Indo-European root. Related to first and fore (thence before), from Proto-Germanic.

Etymology from Wiktionary, CC BY-SA 3.0