to stop the flow of blood or other liquid from (a wound, leak, etc.).
3.
Archaic. to check, allay, or extinguish.
verb (used without object)
4.
to stop flowing, as blood; be stanched.
noun
5.
Also called flash-lock, navigation weir. a lock that, after being partially emptied, is opened suddenly to send a boat over a shallow place with a rush of water.
C14: from Old French estanchier, from Vulgar Latin stanticāre (unattested) to cause to stand, from Latin stāre to stand, halt
Word Origin and History for stanch
v.
"to stop the flow of" (especially of blood), c.1300, from Old French estanchier "cause to cease flowing, stop, hinder," from Vulgar Latin *stancare, perhaps contracted from *stagnicare, from Latin stagnum "pond, pool" (see stagnate).