ball-bearing

n (a) type of bearing(5) in which small steel balls are used to reduce friction 滚珠轴承. (b) (usu pl 通常作复数) any of these balls （滚珠轴承的）滚珠.

balance of payments, balance of power, balance of trade, balance sheet, balanced, balcony, bald, bald eagle, balderdash, balding, baldly, baldness, bale, baleful, balefully, balk, balk (also baulk), balky, ball, ball game, ball-point, ball-point pen, ballad, ballade, ballast, ballboy, ballgirl, ballcock, ballerina, ballet, ballet-dancer, ballistic missile, ballistics, ballocks, ballocks (also bollocks), balloon, balloon-borne, ballooning, balloonist, ballot, ballot-box,