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

御食い初め[okuizome] weaning ceremony
食っ付く[kuttsuku] to adhere to
食っ付ける[kuttsukeru] to attach
ぼりぼり食べる[boriboritaberu] to eat with a munching or crunching sound
インスタント食品[insutantoshokuhin] instant foods

レトルト食品[retorutoshokuhin] packed and sterilised food
衣食[ishoku] food and clothing
衣食住[ishokujuu] necessities of life (food, clothing & shelter)
育児食[ikujishoku] baby food
一夜乞食[ichiyakojiki] (a) person made homeless by fire