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

厨子[zushi] miniature shrine with double doors (used to store important Buddhist items such as sutras, etc.)
厨房[chuubou] kitchen
庖厨[houchuu] kitchen
厨二病[chuunibyou] behaving in a way characteristic of teenagers going through puberty, esp. by being overly self-conscious

厨子棚[zushidana] cabinet with double doors (used by the nobility to store books, etc.)
厨人[chuujin] chef
厨宰[chuusai] chef
厨芥[chuukai] kitchen waste

くる病[kurubyou] rickets
アルツハイマー病[arutsuhaimaabyou] Alzheimer's disease
ケーソン病[keesonbyou] caisson disease
ハンセン病[hansenbyou] Hansen's disease
マレック病[marekkubyou] Marek's disease

悪病[akubyou] bad health
胃病[ibyou] stomach trouble
遺伝病[idenbyou] hereditary (genetic) disease
いもち病[tounetsubyou] rice blight
疫病神[yakubyougami] jinx (lit: god of pestilence)