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

一個[ikko] piece
各個[kakko] every one
個室[koshitsu] private room
個条[kajou] article
個人[kojin] individual

個人タクシー[kojintakushii] privately owned taxi
個人教授[kojinkyouju] private instruction
個人経営[kojinkeiei] private management
個人個人[kojinkojin] individual

に当たって[niatatte] at the time of (ind. opportunity or situation where something should be done)
一騎当千[ikkitousen] being a match for a thousand
一指当たり[ichiyubiatari] span
一人当たり[hitoriatari] per person
一人当て[hitoriate] per person

引当[hikiate] mortgage
引当金[hikiatekin] reserves
押し当てる[oshiateru] to push (something) against
穏当[ontou] proper
過当[katou] excessive