balsa

n (a) [U] lightweight wood used for making models, rafts, etc 轻木（轻质木材, 用以制作模型、木筏等）. (b) [C] tropical American tree from which this comes 轻木树（生长於热带美洲）.

ballistic missile, ballistics, ballocks, ballocks (also bollocks), balloon, balloon-borne, ballooning, balloonist, ballot, ballot-box, ballpark, ballroom, balls-up, bally, ballyhoo, balm, balmily, balminess, balmy, baloney, balsam, Baltic, baluster, balustrade, bamboo, bamboo-shoot, bamboozle, ban, banal, banality, banana, banana republic, banana skin, band, Band-aid, band-saw, bandage, bandanna, bandbox, bandeau,