charlock

noun

char·​lock ˈchär-ˌläk 

-lək

: an Old World mustard (Rhamphospermum arvense synonym Brassica arvensis) that is a common weed in grain fields

called also wild mustard

Word History

Etymology

Middle English cherlok, from Old English cerlic

First Known Use

before the 12th century, in the meaning defined above