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

何の位[donogurai] how long
リーダーシップ的地位[riidaashipputekichii] leadership position
安定同位体[anteidouitai] stable isotope
位階[ikai] court rank
位階勲等[ikaikuntou] court rank and honors

位冠[ikan] ancient headgear showing rank
位官[ikan] rank and official position
位記[iki] court rank diploma
位記追贈[ikitsuisou] conferment of posthumous rank

位冠[ikan] ancient headgear showing rank
衣冠[ikan] kimono and ancient head-dress
栄冠[eikan] laurels
王冠[oukan] crown
加冠[kakan] crowning a boy with a traditional cap for the first time at a coming-of-age ceremony

花冠[kakan] corolla (of flower)
冠を曲げる[kanmuriwomageru] to become displeased
冠位[kani] system indicating court ranks by headgear colors (colours)
冠婚葬祭[kankonsousai] important ceremonial occasions in family relationships
冠詞[kanshi] article

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)

位階[ikai] court rank
位階勲等[ikaikuntou] court rank and honors
一階[ikkai] one floor
音階[onkai] musical scale
下層階級[kasoukaikyuu] proletariat

階下[kaika] lower floor
階級[kaikyuu] (social) class
階級章[kaikyuushou] rank insignia
階級闘争[kaikyuutousou] class struggle