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

御目出度う御座います[omedetougozaimasu] congratulations
一座[ichiza] party
円座[enza] sitting in circle
奥座敷[okuzashiki] inner parlor
横座標[ouzahyou] abscissa

王座[ouza] throne
おうし座[oushiza] Taurus (constellation)
おひつじ座[ohitsujiza] Aries (constellation)
おとめ座[otomeza] Virgo (constellation)
下座[geza] squatting

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

イ短調[itanchou] A minor
ト短調[totanchou] G minor
ニ短調[nitanchou] D minor
ハ短調[hatanchou] C minor
ヘ短調[hetanchou] F minor

ホ短調[hotanchou] E minor
ロ短調[rotanchou] B minor
一長一短[icchouittan] (something having its) merits and demerits
簡短[kantan] simple
気が短い[kigamijikai] quick-tempered

遠隔講義[enkakukougi] distance learning
休講[kyuukou] lecture cancellation
公開講座[koukaikouza] extension lectures
講演[kouen] lecture
講演会[kouenkai] lecture (esp. special engagement by noted speaker)

講義[kougi] lecture
講座[kouza] academic teaching unit
講師[koushi] lecturer
講習[koushuu] short course
講習会場[koushuukaijou] training center

ゴミ集積場[gomishuusekijou] village garbage collection point
英字集合[eijishuugou] alphabetic character set
家集[kashuu] poet's poetical works
歌集[kashuu] anthology
画集[gashuu] book of paintings in print

会集[kaishuu] audience
解集合[kaishuugou] set of solutions
寄集め[yoseatsume] mish-mash
寄せ集める[yoseatsumeru] to put together
寄り集まる[yoriatsumaru] to gather together