悪友[akuyuu] undesirable friend
畏友[iyuu] one's esteemed friend
益友[ekiyuu] good friend
学友[gakuyuu] school friend
級友[kyuuyuu] classmate

旧友[kyuuyuu] crony
血友病[ketsuyuubyou] haemophilia
交友[kouyuu] friend
交友関係[kouyuukankei] one's relationships
校友[kouyuu] schoolmate

阿吽の呼吸[aunnokokyuu] the harmonizing, mentally and physically, of two parties engaged in an activity
歓呼[kanko] acclamation
関数呼出し[kansuuyobidashi] function call
呼び回る[yobimawaru] to call out (for someone)
呼び覚ます[yobisamasu] to wake up

呼掛ける[yobikakeru] to call out to
呼寄せる[yobiyoseru] to call
呼起す[yobiokosu] to wake someone (by calling for them)
呼び迎える[yobimukaeru] to send for
呼び込む[yobikomu] to call in

異類[irui] varieties
一類[ichirui] same kind
円虫類[enchuurui] round worms
塩類[enrui] salts
塩類溶液[enruiyoueki] saline

貝類[kairui] shellfish
柑橘類[kankitsurui] citrus fruits
希土類[kidorui] rare earth
魚貝類[gyokairui] marine products
魚類[gyorui] fish