Meaning

noun any creative group active in the innovation and application of new concepts and techniques in a given field (especially in the arts)

noun the leading units moving at the head of an army

noun (Great Britain) a closed railroad car that carries baggage or freight

originFrom Latin vannus (“a van, or fan for winnowing grain”): compare French van and English fan, winnow. Doublet of fan.

Etymology from Wiktionary, CC BY-SA 3.0