weir weir /ˈwiːr/

noun

1. () A low dam built across a stream to raise its level or divert its flow  ( weir )
   a low dam built across a stream to raise its level or divert its flow
    The weir controlled the flow of water to the mill.
   The weir controlled the flow of water to the mill.
   
   
2. A fence or wattle built across a stream to catch or retain fish  ( weir )
   a fence or wattle built across a stream to catch or retain fish
    Fishermen constructed a weir across the river to help them catch more fish.
   Fishermen constructed a weir across the river to help them catch more fish.