睾丸

[ noun ]
one of the two male reproductive glands that produce spermatozoa and secrete androgens
<noun.body>
she kicked him in the balls and got away

bollock \bollock\ n.
one of the two male reproductive glands; a testis; -- usually
spelled {ballock}, and usually used in the plural.

Syn: gonad, testicle, ball, nut, egg.
[WordNet 1.5 +PJC]

2. a pulley-block at the head of a topmast.

Syn: bullock block.
[WordNet 1.5]