Meaning

adjective equally distant from the extremes

adjective at a point midway between two extremes

adjective including only half or a portion

originFrom Middle English halfwey, from Old English healfweġ (“half-way”), equivalent to half- + way. Compare partway. Cognate with Saterland Frisian hoolfwais (“halfway”), Dutch halfweg (“halfway”), German halbwegs (“halfway”), Danish halvvejs (“halfway”), Swedish halvvägs (“halfway”).

Etymology from Wiktionary, CC BY-SA 3.0