悪球[akkyuu] hard ball to hit
逸球[ikkyuu] muffed ball
衛星地球局[eiseichikyuukyoku] (satellite) earth station
眼球[gankyuu] eyeball
気球[kikyuu] balloon

球戯[kyuugi] billiards
球技[kyuugi] ball game (e.g. baseball, tennis, soccer)
球菌[kyuukin] coccus
球形[kyuukei] globular or spherical shape