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

安全期[anzenki] safe period
暗黒期[ankokuki] eclipse period
一期[ichigo] one's life time
一期[ikki] one term
一期一会[ichigoichie] once-in-a-lifetime encounter (hence should be cherished as such)

一周期[isshuuki] period (in astronomy)
一定期間[itteikikan] fixed interval
延期[enki] postponement
延期になる[enkininaru] to be postponed
沖積期[chuusekiki] alluvial period

あっとゆう間に[attoiumani] just like that
此間[konaida] the other day
此の間[konokan] the other day
間誤付かせる[magotsukaseru] to fluster
間誤付く[magotsuku] to be confused

クローン人間[kuroonningen] (human) clone
シゾイド人間[shizoidoningen] schizoid person
ベクトル空間[bekutorukuukan] vector space
π中間子[paichuukanshi] pi meson
位相空間[isoukuukan] phase space (physics)