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long ago; a long time ago; already
その話は疾っくに知っているよ、古い話だ。
I've known about that for a long time, it's old news.
彼は疾っくに帰宅して今は寝ているはずだ。
He should have gone home long ago and is sleeping now.
問題は疾っくに解決していて心配は無用です。
The problem was solved long ago, no need to worry.