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

アラビア数字[arabiasuuji] Arabic numeral
キリル文字[kirirumoji] Cyrillic character
ギリシア文字[girishiamoji] Greek character
羅馬字[roomaji] Latin alphabet
ロシア文字[roshiamoji] Russian character

異体字[itaiji] kanji variants
一字[ichiji] letter
一字千金[ichijisenkin] word of great value
一丁字[itteiji] single letter or character
一文字[ichimonji] straight line

空オケ[karaoke] karaoke (singing to taped accompaniment)
ベクトル空間[bekutorukuukan] vector space
茜さす空[akanesasusora] glowing sky
圧搾空気[assakukuuki] compressed air
圧縮空気[asshukukuuki] compressed air

位相空間[isoukuukan] phase space (physics)
宇宙空間[uchuukuukan] outer space
雨空[amazora] rainy sky
英国航空[eikokukoukuu] British Airways
仮想空間[kasoukuukan] virtual space (e.g. in computer graphics)