Meaning

noun the post or function properly or customarily occupied or served by another

originEtymology tree Proto-Indo-European *stel-der. Proto-Italic *stlokos? Old Latin stlocus Latin locus Old French leu Middle French lieubor. English lieu Borrowed from Middle French lieu, from Old French leu, from Latin locum, accusative of locus (“place”). Doublet of locus. Attested earlier and in Middle English only as part of the partially calqued phrase in lieu of.

Etymology from Wiktionary, CC BY-SA 3.0