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

悪条件[akujouken] unfavorable conditions
暗殺事件[ansatsujiken] assassination
案件[anken] matter in question
一件[ikken] matter

怪事件[kaijiken] mystery case
基本条件[kihonjouken] basic conditions
刑事々件[keijijiken] criminal case
件数[kensuu] number of events (e.g. accidents, crimes, meetings, housing starts, hits on a web page)