九つ[kokonotsu] nine
九夏[kyuuka] summer
九回戦[kyuukaisen] regulation game
九官鳥[kyuukanchou] hill myna (species of mynah bird, Gracula religiosa)
九牛の一毛[kyuugyuunoichimou] mere fraction

九々[kuku] multiplication table
九月[kugatsu] September
九工大[kyuukoudai] Kyushu Institute of Technology
九穀[kyuukoku] the nine grains
九死に一生[kyuushiniisshou] narrow escape from death

井泉[seisen] (water) well
黄泉[kousen] underground spring
温泉[onsen] spa
九泉[kyuusen] hades
源泉[gensen] source

古泉学[kosengaku] numismatics
鉱泉[kousen] mineral spring
泉貨紙[senkashi] reclaimed paper
泉水[sensui] fountain