to understand a hint and behave accordingly. I said I didn't want to see you anymore. Can't you take a hint? I don't like you. Sure I can take a hint, but I'd rather be told directly.
to understand or do something that is communicated indirectly I can take a hint – if you don't want to talk about it, that's OK with me.“Weren't you going to check your messages?” she asked. I took the hint and left.
Also, take the hint. Accept an indirect or covert suggestion, as in Evelyn took the hint and quietly left the room. This idiom was first recorded in 1711.