助番[sukeban] leader of a female gang
ブロック番号[burokkubangou] block number
暗唱番号[anshoubangou] personal identification number
一貫番号[ikkanbangou] serial number
一番[ichiban] best

一番[hitotsugai] pair
一番鶏[ichibandori] first cockcrowing
一番手[ichibante] first player
一番乗り[ichibannori] leader of a charge
一番線[ichibansen] track no. 1

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)