いい年をして[iitoshiwoshite] (in spite of) being old enough to know better
亥年[idoshi] year of the boar
一箇年[ikkanen] one year
一周年[isshuunen] one full year
一年以内に[ichineninaini] within a year

一年間[ichinenkan] (period of) one year
一年生[ichinensei] annual (plant)
一年草[ichinensou] annual (plant)
一年ぢゅう[ichinenjuu] all year round
一両年[ichiryounen] (a) year or two

明白[meihaku] obvious
明白[akarasama] plain
明かん[akan] useless
また明日[mataashita] see you tomorrow
意識不明[ishikifumei] unconscious

印鑑証明[inkanshoumei] certification of official registration of a seal
飲み明かす[nomiakasu] to drink the night away
解明[kaimei] clarification
明ける[akeru] to open (a door, etc.)
明け放す[akehanasu] to open wide (doors, windows, etc.)

安全期[anzenki] safe period
暗黒期[ankokuki] eclipse period
一期[ichigo] one's life time
一期[ikki] one term
一期一会[ichigoichie] once-in-a-lifetime encounter (hence should be cherished as such)

一周期[isshuuki] period (in astronomy)
一定期間[itteikikan] fixed interval
延期[enki] postponement
延期になる[enkininaru] to be postponed
沖積期[chuusekiki] alluvial period