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

一秒[ichibyou] one second
数秒[suubyou] several seconds
寸秒[sunbyou] a moment
秒針[byoushin] second hand (of clock)
秒速[byousoku] per second

秒読み[byouyomi] countdown
分秒[funbyou] moment
毎秒[maibyou] every second
秒時計[byoudokei] stop watch