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

お風呂に入る[ofuronihairu] to take a bath
鍬入れ式[kuwaireshiki] ground-breaking ceremony
塵入[gomiire] trashcan
キー入力[kiinyuuryoku] key (input)
ビジネススクール入学共通試験[bijinesusukuurunyuugakukyoutsuushiken] business school entrance test

メスを入れる[mesuwoireru] to operate
圧入[atsunyuu] indentation
移入[inyuu] importation
一寝入り[hitoneiri] nap
一入[hitoshio] still more

医院[iin] doctor's office (surgery)
医院長[iinchou] head doctor
育児院[ikujiin] orphanage
一院制[ichiinsei] unicameral system
院外[ingai] outside congress

院号[ingou] former emperor (or his empress, imperial princesses, etc.)
院政[insei] government by cloistered emperors
院生[insei] graduate student
院宣[inzen] imperial command (decree)
院長[inchou] director