Simple Definition of weir

from our Learner's Dictionary

weir

noun

plural weirs
: a low wall or dam built across a stream or river to raise the level of the water or to change the direction of its flow

Cite this Entry

“Weir.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/weir. Accessed 21 Jun. 2026.

More from Merriam-Webster on weir

More from Merriam-Webster