Etymology
From Middle English darnel, dernel, from Old Northern French darnelle ( > dialectal French dernelle, darnette), of Germanic origin, possibly Proto-West Germanic *darjan (“to harm, injure”). Displaced native Old English boþen.
Related to Walloon darne, derne (“stunned, dazed, drunk”), Middle Dutch verdarnt, verdaernt (“stunned, dumbfounded, angry”). The association with being dazed or drunkenness is due to the well-known intoxicating effects of the plant.