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

御湯[oyu] hot water
塩湯[shioyu] hot salt water (incl. bath)
温湯[ontou] comfortably hot bath
下湯[shimoyu] sitz bath
そと湯[sotoyu] open air bath (in an inn, onsen, etc.)

給湯[kyuutou] hot-water supply
給湯器[kyuutouki] hot-water heater
腰湯[koshiyu] sitting bath
重湯[omoyu] thin rice gruel
出で湯[ideyu] hot spring