Ago

наречие тому назад Например: long ago — давно not long / a while ago — недавно It was five years ago that we met. — Мы встретились пять лет назад.

Большой англо-русский словарь

Ago

adjective or adverb Etymology: Middle English agon, ago, from past participle of agon to pass away, from Old English āgān, from ā- (perfective prefix) + gān to go — more at abide, go earlier than the present time Example: 10 years ago

Merriam-Webster's Collegiate Dictionary