1.  ball;  sphere;  globe;  orb
2.  bead (of sweat, dew, etc.);  drop;  droplet
3.  ball (in sports)
esp. 球
4.  pile (of noodles, etc.)
5.  bullet
esp. 弾; also written as 弾丸
6.  bulb (i.e. a light bulb)
esp. 球
7.  lens (of glasses, etc.)
8.  bead (of an abacus)
esp. 玉,珠
9.  ball (i.e. a testicle)
esp. 玉
10.  gem;  jewel (esp. spherical; sometimes used figuratively);  pearl
esp. 玉,珠; also written as 璧
11.  female entertainer (e.g. a geisha)
12.  person (when commenting on their nature);  character
13.  item, funds or person used as part of a plot
14.  egg
16.  precious;  beautiful;  excellent