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

彼の人[anohito] he
殆どの人[hotondonohito] most people
アメリカ人[amerikajin] American person
クローン人間[kuroonningen] (human) clone
シゾイド人間[shizoidoningen] schizoid person

ドイツ人[doitsujin] German person
ベトナム人[betonamujin] Vietnamese (person)
ペルシア人[perushiajin] Persian person
ユダヤ人[yudayajin] Jew
愛人[aijin] lover

これと同じ[koretoonaji] the same as this
と同じ様に[toonajiyouni] in the same way as
安定同位体[anteidouitai] stable isotope
異句同音[ikudouon] in concert
異口同音に[ikudouonni] in one voice

異同[idou] difference
一口同音[ikkudouon] reading in unison
一視同仁[isshidoujin] loving every human being with impartiality
一心同体[isshindoutai] being one in body and soul
一同[ichidou] all present

行けない[ikenai] wrong
行る[yaru] to send
オリエント急行[orientokyuukou] Orient express
カ行[kagyou] classification for Japanese verb with the dictionary form ending in "ku"
ガ行[gagyou] classification for Japanese verb with the dictionary form ending in "gu"

サ行[sagyou] classification for Japanese verb with the dictionary form ending in "su"
ザ行[zagyou] classification for Japanese verb with the dictionary form ending in "zu"
スパイ行為[supaikoui] espionage
タ行[tagyou] classification for Japanese verb with the dictionary form ending in "tsu"
ダ行[dagyou] classification for Japanese verb with the dictionary form ending in "dzu"