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

一億[ichioku] 100,000,000
億ション[okushon] (luxury) apartment
億円[okuen] 100,000,000 yen
億劫[okkuu] troublesome
億兆[okuchou] the people

億万長者[okumanchouja] billionaire
十億[juuoku] 1,000,000,000
十万億土[juumanokudo] eternity
数億年[suuokunen] several hundred million years