Meaning of 今更 in Japanese

Definition of 今更

いまさら(imasara) 【今更 ·今さら】

(adv, n) now (after such a long time); at this late hour (i.e. it is too late for something)
いまさら後悔しても無駄だ。
It's no use regretting it now.

今更いまさらそんなことを言った日ひにゃ、火に油を注ぐひにあぶらをそそぐことになるだけだよ。

For you to come out and say that kind of thing now would just be pouring oil on the fire.

ここまで計画けいかくしたするのに、今更いまさらやめるって言わないでよ。

Don't tell me you're going to back out after all the plans we've made.

How long are you going to keep whimpering about that? You can't change the past.