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

花束[hanataba] bunch of flowers
会う約束[auyakusoku] rendezvous
結束[kessoku] union
検束[kensoku] arrest
牽束[kensoku] restraint

口約束[kuchiyakusoku] verbal promise
拘束[kousoku] restriction
黒装束[kuroshouzoku] black clothes
札束[satsutaba] roll of banknotes
収束[shuusoku] convergence

草臥れる[kutabireru] to get tired
遺草[isou] posthumous works
一年草[ichinensou] annual (plant)
詠草[eisou] draft poem
下草[shitakusa] undergrowth

仮名草紙[kanazoushi] story in the kana
伽草子[togizoushi] fairy-tale book
海草[kaisou] marine plant
乾草[kansou] hay
甘草[kanzou] liquorice

草鞋[waraji] straw sandals
草鞋虫[warajimushi] wood louse

二束の草鞋[nisokunowaraji] many irons in the fire
草鞋を脱ぐ[warajiwonugu] to complete one's journey