Probably from Middle French and Old French drap, either:
from Late Latin drappus, most likely from Gaulish *drappo, from Proto-Indo-European *drep-; or
from Frankish *drapi, *drāpi, from Proto-Germanic *drap-, *drēp-, from *drepaną, from Proto-Indo-European *dʰrebʰ-.
The English word is cognate with Ancient Greek δρέπω, Avestan 𐬛𐬭𐬀𐬟𐬱𐬀, Lithuanian drãpanos, Old Norse trefja, trof, Sanskrit द्रापि, Serbo-Croatian drápati).
The origin of the noun is Unknown; compare Middle English drabelen, drablen, draplen, and Low German drabbe, drabbeln, and Old Norse drabba, the latter three ultimately from Proto-Germanic *drepaną, from Proto-Indo-European *dʰreb-. The word is also likely to be related to Dutch drab, Irish drabog, Scottish Gaelic drabag.