ちょっと一杯[chottoippai] let's have a quick drink
ばつ一[batsuichi] being once divorced
一向[hitaburu] nothing but
サラダ一皿[saradahitosara] plate of salad

安全第一[anzendaiichi] safety first
一か八か[ichikabachika] sink or swim
一っ走り[hitoppashiri] spin (as in 'take a car for a spin')
一つ一つ[hitotsuhitotsu] one-by-one

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

御目出度う御座います[omedetougozaimasu] congratulations
駄目になる[dameninaru] to spoil
繋ぎ目[tsunagime] joint
軽目焼[karumeyaki] hard caramelized sugar candy
駄目押し[dameoshi] making doubly sure

一つ目[hitotsume] one-eyed
一合目[ichigoume] the start of a climb up a hill
一丁目[icchoume] Block 1
ひと目[ichimoku] (a) glance
一目惚れ[hitomebore] to be taken with someone at first sight (similar to "love at first sight", but not as strong)