一元[ichigen] unitary
一元化[ichigenka] unification
一元的[ichigenteki] monistic
一元論[ichigenron] monism
一次元[ichijigen] one dimensional

一新紀元[isshinkigen] new era
隠元[ingen] beans
隠元豆[ingenmame] common bean (Phaseolus vulgaris)
家元[iemoto] head of a school (of music, dance)
火の元[hinomoto] origin of fire

御目出度う御座います[omedetougozaimasu] congratulations
駄目になる[dameninaru] to spoil
繋ぎ目[tsunagime] joint
軽目焼[karumeyaki] hard caramelized sugar candy
駄目押し[dameoshi] making doubly sure

一つ目[hitotsume] one-eyed
一合目[ichigoume] the start of a climb up a hill
一丁目[icchoume] Block 1
ひと目[ichimoku] (a) glance
一目惚れ[hitomebore] to be taken with someone at first sight (similar to "love at first sight", but not as strong)

許りに[bakarini] (simply) because
允許[inkyo] permission
運転免許[untenmenkyo] driver's license
奥許し[okuyurushi] secret
仮免許[karimenkyo] temporary license

官許[kankyo] official licence
気を許す[kiwoyurusu] to let one's guard down
許し[yurushi] pardon
許す[yurusu] to permit