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)

お大事に[odaijini] take care of yourself
暗黒大陸[ankokutairiku] Dark Continent (i.e. Africa)
伊勢大神宮[isedaijinguu] the Grand Shrines of Ise
伊勢大廟[isetaibyou] the Grand Shrines of Ise
偉大[idai] greatness

医科大学[ikadaigaku] medical school
医大[idai] medical university
井の中の蛙大海を知らず[inonakanokawazutaikaiwoshirazu] parochial
一大[ichidai] one large ...
一大事[ichidaiji] serious affair

御誕生日おめでとうございます[otanjoubiomedetougozaimasu] Happy Birthday
また明日[mataashita] see you tomorrow
旭日[kyokujitsu] rising sun
旭日昇天[kyokujitsushouten] full of vigor and vitality (like the rising sun) (vigour)
或日[aruhi] one day (e.g. "one day while studying, ..")

一日の長[ichijitsunochou] superiority
一日一日[ichinichiichinichi] gradually
一日一夜[ichinichiichiya] all day and night
一日増しに[ichinichimashini] day by day
一日置き[ichinichioki] every other day

スポ根[supokon] heart (athletics)
羽根[hane] feather
円屋根[maruyane] dome
家根[yane] roof
卸し大根[oroshidaikon] grated daikon

下し大根[oroshidaikon] grated radish
下種根性[gesukonjou] mean feelings
夏大根[natsudaikon] summer daikon
禍根[kakon] root of evil
塊根[kaikon] tuberous root