bois de vache

[ bwah duh vash ]
/ ˌbwɑ də ˈvæʃ /

noun

dried buffalo dung, used as fuel by Canadian and U.S. fur trappers in the 18th and 19th centuries.

Origin of bois de vache

1835–45, Americanism; < Prairie Canadian French: literally, buffalo wood ( vache buffalo, French: cow)