海亀[umigame] sea turtle
亀の子[kamenoko] young turtle (tortoise)
亀の手[kamenote] barnacle
亀鑑[kikan] pattern
亀甲[kikkou] tortoise shell

亀頭[kitou] glans (esp. glans penis)
亀裂[kiretsu] crack
水亀[ishigame] any turtle of the genus Mauremys (esp. the Japanese pond turtle, Mauremys japonica)
盲亀[mouki] blind turtle

偉功[ikou] great deed
遺功[ikou] works following the deceased
気功[kikou] breathing exercise
九仞の功[kyuujinnokou] spectacular success
勲功[kunkou] merits

軍功[gunkou] meritorious war service
蛍雪の功[keisetsunokou] the fruit of diligent study
功業[kougyou] exploit
功罪[kouzai] both good and bad
功績[kouseki] achievements

いい年をして[iitoshiwoshite] (in spite of) being old enough to know better
亥年[idoshi] year of the boar
一箇年[ikkanen] one year
一周年[isshuunen] one full year
一年以内に[ichineninaini] within a year

一年間[ichinenkan] (period of) one year
一年生[ichinensei] annual (plant)
一年草[ichinensou] annual (plant)
一年ぢゅう[ichinenjuu] all year round
一両年[ichiryounen] (a) year or two

華甲[kakou] aged 61
介甲[kaikou] crust-like shell
機甲[kikou] armour (e.g. tank)
龜甲[kikou] tortoise shell

甲乙[kouotsu] A and B
甲乙丙[kouotsuhei] ABC
甲殻[koukaku] carapace
甲殻類[koukakurui] crustacean