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

馬酔木[asebi] Japanese andromeda (Pieris japonica)
馬鈴薯[jagaimo] potato (Solanum tuberosum)
じゃじゃ馬[jajauma] restive horse
玖馬[kyuuba] Cuba
トロイの木馬[toroinomokuba] Trojan horse

巴奈馬[panama] Panama
馬克[maruku] mark
羅馬字[roomaji] Latin alphabet
ワープロ馬鹿[waapurobaka] someone whose kanji-writing ability has suffered due to overreliance on the kana-to-kanji conversion systems used to input Japanese text on a computer
愛馬[aiba] favourite horse