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

ハチ公[hachikou] statue of Hachiko (a dog) at Shibuya station
郭公[kakkou] common cuckoo (Cuculus canorus)
株式公開[kabushikikoukai] stock offering (to the public)
蒲公英[tanpopo] dandelion (esp. species Taraxacum platycarpum)
官公庁[kankouchou] government administration office

丸公[marukou] official price
勤め奉公[tsutomeboukou] apprenticeship
公平[kinpira] chopped burdock root (and sometimes carrot) cooked in sugar and soy sauce
公孫樹[kousonju] ginkgo (Ginkgo biloba)

育児園[ikujien] baby nursery
園芸[engei] horticulture
園児[enji] kindergarten pupil
園長[enchou] head of a garden
園遊会[enyuukai] garden party

果樹園[kajuen] orchard
開園[kaien] opening, either for the day or a "grand opening" (e.g. theme park, botanical garden etc.)
学園[gakuen] academy
学園祭[gakuensai] school festival

海鷂魚[ei] ray (fish)
井の中の蛙大海を知らず[inonakanokawazutaikaiwoshirazu] parochial
一天四海[ittenshikai] the world
雲海[unkai] sea of clouds
沿海[enkai] coast

遠海[enkai] deep sea
黄海[koukai] Yellow Sea
温海[atsumi] warm sea
海の幸[uminosachi] seafood