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

祈誓[kisei] vow
偽り誓う[itsuwarichikau] to swear falsely
偽誓[gisei] perjury
修道誓願[shuudouseigan] vows of religious orders
誓い[chikai] oath

誓う[chikau] to swear
誓願[seigan] vow (e.g. religious)
誓言[seigen] attestation
誓文[seimon] written oath
誓約[seiyaku] written vow

データの先頭[deetanosentou] beginning of data
一頭[ittou] one large animal (horses, cattle, etc.)
一頭立て[ittoudate] one-horse (carriage)
咽頭[intou] pharynx
駅頭[ekitou] station

音頭[ondo] leading a group of people
会頭[kaitou] society president
街頭[gaitou] in the street
核弾頭[kakudantou] nuclear warhead
巻頭[kantou] opening page of book