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

医務[imu] medical affairs
医務室[imushitsu] doctor's office
外務[gaimu] foreign affairs
外務省[gaimushou] Ministry of Foreign Affairs
外務大臣[gaimudaijin] Minister for Foreign Affairs

義務[gimu] duty
義務教育[gimukyouiku] compulsory education
急務[kyuumu] urgent business
教務[kyoumu] school affairs
業務[gyoumu] business

運輸省[unyushou] Ministry of Transport
外務省[gaimushou] Ministry of Foreign Affairs
各省[kakushou] each ministry
冠省[kanshou] Forgive me for dispensing with the preliminaries, but I hasten to inform you that...
帰省[kisei] homecoming

教育省[kyouikushou] Department of Education
省みる[kaerimiru] to look back (e.g. over shoulder or at the past)
厚生省[kouseishou] Ministry of Health and Welfare (now Ministry of Health, Labour and Welfare)
国防総省[kokubousoushou] National Military Establishment
国務省[kokumushou] State Department