- a low dam built in a river to back up or divert water, as for a mill; milldam
- a fence, as of brushwood or stakes, built in a stream, channel, etc., for catching fish
- an obstruction placed in a stream, diverting the water through a prepared aperture for measuring the rate of flow
Origin of weirMiddle English were from Old English wer, weir, dam (akin to German wehr) from base of werian, to defend, dam up from Indo-European base an unverified form wer-, to shut up, cover
- A fence or wattle placed in a stream to catch or retain fish.
- A dam placed across a river or canal to raise or divert the water, as for a millrace, or to regulate or measure the flow.
Origin of weirMiddle English were from Old English wer ; see wer-4 in Indo-European roots.