一ひと昔むかし

noun

a while ago; an age ago; about a decade ago

Refers to a past period felt to be separated from the present. It can literally suggest roughly ten years ago, but often means more broadly 'a previous era' or 'a long time ago,' especially in 一昔前.

• 一ひと昔むかし前まえなら、駅えきで切きっ符ぷを買かうのが普ふ通つうだった。

  A while back, it was normal to buy tickets at the station.

• その考かんがえ方かたはもう一ひと昔むかし前まえのものだ。

  That way of thinking is already from a bygone era.