一廓[ikkaku] one block
外廓[gaikaku] outer wall (e.g. castle)
城廓[joukaku] fortress
遊廓[yuukaku] red light district

輪廓[rinkaku] contour
廓清[kakusei] purification
廓詞[kuruwakotoba] sociolect or secret language used by prostitutes in red-light districts (Edo period)

カバー曲[kabaakyoku] remake of another artist's song (a "cover")
サイン曲線[sainkyokusen] sinusoid
愛唱曲[aishoukyoku] favourite song
委曲[ikyoku] details
一曲[ikkyoku] tune (melody, piece of music)

迂曲[ukyoku] meander
円曲[enkyoku] roundabout way (of speaking or working)
円錐曲線[ensuikyokusen] conic curve
円舞曲[enbukyoku] waltz (composition)
演曲[enkyoku] musical program

ダイヤの指輪[daiyanoyubiwa] diamond ring
一次線輪[ichijisenrin] primary coil
一輪[ichirin] one flower
一輪車[ichirinsha] unicycle
花輪[hanawa] wreath

競輪[keirin] keirin
金輪際[konrinzai] the deepest bottom of the earth
九輪[kurin] kurin (nine vertically stacked rings of a pagoda finial)
結婚指輪[kekkonyubiwa] wedding ring
月の輪[tsukinowa] moon (esp. full moon)

一郭[ikkaku] one block
外郭[gaikaku] outer wall (e.g. castle)
外郭団体[gaikakudantai] auxiliary organization
郭公[kakkou] common cuckoo (Cuculus canorus)
胸郭[kyoukaku] chest

五稜郭[goryoukaku] five-sided fortification
城郭[joukaku] fortress
郭公[hototogisu] lesser cuckoo (Cuculus poliocephalus)
遊郭[yuukaku] red light district
輪郭[rinkaku] contour