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

偉挙[ikyo] excellent deeds
一挙[ikkyo] one effort
一挙一動[ikkyoichidou] one's every action
一挙手一投足[ikkyoshuittousoku] slight effort
一挙両得[ikkyoryoutoku] killing two birds with one stone

一斉検挙[isseikenkyo] wholesale arrest
科挙[kakyo] Chinese higher civil service examinations
快挙[kaikyo] brilliant achievement
旗挙[hataage] raising an army
挙げた[ageta] brought up (e.g. topic)