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

愛唱[aishou] fondness for singing
愛唱歌[aishouka] (one's) favourite song
愛唱曲[aishoukyoku] favourite song
暗唱[anshou] recitation
暗唱番号[anshoubangou] personal identification number

詠唱[eishou] aria
歌唱[kashou] song
吟唱[ginshou] recital
合唱[gasshou] chorus
合唱隊[gasshoutai] chorus

意味深重[imishinchou] with profound (often hidden) meaning
一重ね[hitokasane] suit
一重継ぎ[hitoetsugi] sheep bend (knot)
一重桜[hitoezakura] cherry tree bearing single blossoms
荷重[kajuu] load

過重[kajuu] overweight
気が重い[kigaomoi] depressed
貴重[kichou] precious
貴重品[kichouhin] valuables
起重機[kijuuki] crane