bosk

From Middle English bosk, busk, variants of bush (“grove, wood; thicket, underbrush; bush; branch of a shrub or tree”), from Old English busc (attested only in place names), likely from Anglo-Latin bosca (“firewood”), from Late Latin busca, buscus, boscus (“wood; woodland”), from Frankish and Proto-West Germanic *busk, from Proto-Germanic *buskaz (“bush, thicket”), probably from Proto-Indo-European *bʰuH- (“to become, grow, appear”).
The English word is cognate with Dalmatian buasc (“forest; wood”), French bois (“wood (material); wood, woodland”), Italian bosco (“wood (wooded area)”), Middle Dutch bosch, busch (modern Dutch bos (“forest; wood”)), Norwegian busk (“bush, shrub”); Occitan boscs, Old High German busk (“bush”) (Middle High German busch, bosch, modern German Busch (“bush, shrub; brush, scrub”)), Portuguese bosque (“grove”), Spanish bosque (“forest”), West Frisian bosk (“forest”).
Doublet of bush.
Alternatively, the modern word may be a back-formation from bosky (“having abundant bushes, shrubs, or trees”).