お七夜[oshichiya] name-giving ceremony
七つ[nanatsu] seven
七つの海[nanatsunoumi] the seven seas
七屋[nanatsuya] pawnshop
七回忌[shichikaiki] seventh anniversary of a death

七角形[shichikakkei] heptagon
七曲がり[nanamagari] tortuous or spiral (path)
七月[shichigatsu] July
七賢[shichiken] the Seven Wise Men (of Confucius's Analects)

亜種[ashu] subspecies
異機種[ikishu] heterogenous equipment
異種[ishu] different kind (species, variety)
育種[ikushu] (plant) breeding
育種家[ikushuka] (plant) breeder

育種所[ikushujo] (plant) nursery
一種[isshu] species
一粒種[hitotsubudane] an only child
種違い[tanechigai] half-brother
艶種[tsuyadane] love affair