Meaning of AGO in English

AGO

adv. earlier, before the present (ten years ago; long ago). °Note the construction it is ten years ago that (not since) I saw them.

[ ME (ago, agone), past part. of obs. ago (v.) (as A-(2), GO(1)) ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.