御中[onaka] stomach
御話中[ohanashichuu] busy (phone)
アル中[aruchuu] alcoholism
π中間子[paichuukanshi] pi meson
暗中[anchuu] in the dark

暗中摸索[anchuumosaku] groping in the dark
意中[ichuu] one's mind
意中の女[ichuunoonna] sweetheart
井の中の蛙大海を知らず[inonakanokawazutaikaiwoshirazu] parochial
一日中[ichinichijuu] all day long

お使[otsukai] errand
み使い[mitsukai] angel
悪天使[akutenshi] evil angels
かな使い[kanazukai] kana orthography
雁の使い[karinotsukai] (a) letter

旧仮名使い[kyuukanazukai] former (i.e. before the post-WWII reforms) kana usage in writing the readings of kanji
金を使う[kanewotsukau] to spend money
駆使[kushi] free use
軍使[gunshi] truce bearer
権利行使[kenrikoushi] exercise of a right

コンピューター援用生産[konpyuutaaenyouseisan] computer-aided manufacture
コンピューター援用設計[konpyuutaaenyousekkei] computer-aided design
コンピュータ用語[konpyuutayougo] computerese
スキー用品[sukiiyouhin] ski outfit
愛用[aiyou] favorite

悪用[akuyou] abuse
医学用語[igakuyougo] medical term
医用[iyou] medical use
医療用[iryouyou] medical use
一人用[hitoriyou] for one person's use