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

教授[kyouju] professor
個人教授[kojinkyouju] private instruction
交換教授[koukankyouju] exchange professor
口授[kuuju] oral instruction or teaching or method
授かる[sazukaru] to be awarded (e.g. a prize)

授ける[sazukeru] to grant
授業[jugyou] lesson
授業を受ける[jugyouwoukeru] to take a class
授業料[jugyouryou] tuition fee
授爵[jushaku] elevation to peerage

イスラム教徒[isuramukyouto] Muslim
基督教[kirisutokyou] Christianity
キリスト教徒[kirisutokyouto] Christians
ユダヤ教会堂[yudayakyoukaidou] synagogue
安全教育[anzenkyouiku] safety education

異教[ikyou] paganism
一神教[isshinkyou] monotheism
印度教[indokyou] Hinduism
遠隔教育[enkakukyouiku] distance learning
家教[kakyou] tutor

暗部[anbu] dark side (of nature, town, etc.)
鞍部[anbu] col
医学部[igakubu] medical faculty
一局部[ichikyokubu] one part
一部[ichibu] one part

一部始終[ichibushijuu] full particulars
一部分[ichibubun] part
陰部[inbu] the genital area
営業部[eigyoubu] sales department
掩護部隊[engobutai] covering force