Meaning

noun a low dam built across a stream to raise its level or divert its flow

noun a fence or wattle built across a stream to catch or retain fish

originFrom Middle English were, from Old English wer, from werian (“to dam up”), from Proto-West Germanic *warjan, from Proto-Germanic *warjaną, from Proto-Indo-European *wer- (“to cover”); Cognate with Old Norse ver (“station for fishing”), Sanskrit वृणोति (vṛṇóti). Related to warranty.

Etymology from Wiktionary, CC BY-SA 3.0