一も二も無く[ichimonimonaku] unhesitatingly
一言二言[hitokotofutakoto] a word or two
一石二鳥[issekinichou] killing two birds with one stone
一二に及ばず[ichininioyobazu] right away
一姫二太郎[ichihimenitarou] It's good to have a girl first and then a boy

うり二つ[urifutatsu] as alike as two melons (two peas in a pod)
黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
二度[futatabi] again
最小二乗法[saishounijouhou] least-squares method
三十二分音符[sanjuunibuonpu] 32nd note

悪相[akusou] evil countenance
位相[isou] phase (in science)
位相幾何学[isoukikagaku] topology
位相空間[isoukuukan] phase space (physics)
為替相場[kawasesouba] exchange rates

遺産相続[isansouzoku] inheritance
一子相伝[isshisouden] transmission of the secrets of an art, craft, trade or learning from father to only one child
印相[inzou] mudra
運輸相[unyushou] Transport Minister
卸相場[oroshisouba] wholesale price