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

黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
丸十[marujuu] cross in a circle
五十音[gojuuon] the Japanese syllabary
五十音順[gojuuonjun] the syllabary order
五十三次[gojuusantsugi] the 53 Toukaidou stages

五十年祭[gojuunensai] jubilee
五十歩百歩[gojuppohyappo] six of one and a half dozen of the other
五十路[isoji] age fifty
三十戸[sanjikko] thirty houses
三十三所[sanjuusansho] any of a number of sets of thirty-three holy places enshrining Avalokitesvara (esp. those comprising a popular pilgrimage in the Kinki region)

山梔子[kuchinashi] Cape jasmine (Gardenia jasminoides)
悪巫山戯[warufuzake] prank
安土桃山時代[azuchimomoyamajidai] Azuchi-Momoyama period (approx. 1558-1600 CE)
案山子[kakashi] scarecrow
奥山[okuyama] remote mountain

岡山県[okayamaken] Okayama prefecture (Chuugoku area)
下山[gezan] descending (mountain)
夏山[natsuyama] summery mountain
火山[kazan] volcano
火山灰[kazanbai] volcanic ash

比律賓[firippin] Philippines
一律[ichiritsu] evenness
一律減反[ichiritsugentan] reduction in area of rice under cultivation
韻律[inritsu] rhythm
黄金律[ougonritsu] The Golden Rule ("do unto others as you would have them do unto you")

音律[onritsu] metre
戒律[kairitsu] (religious) precept
紀律[kiritsu] order
軍律[gunritsu] martial law
刑律[keiritsu] criminal law