adverb
now (when it's too late); at this late stage
Expresses that an action or realization comes too late to be useful or appropriate. Often carries a nuance of regret, criticism, or futility.
今更後悔しても遅い。
It's too late to regret it now.
今更そんなことを言われても困る。
It's no use telling me that at this stage.
adverb
Used when something is done again after a long interval, often with a sense of 'starting over' or 'revisiting'. Less common than sense 1.
今更ながら、基礎から勉強し直すことにした。
I decided to study again from the basics, even at this late stage.