the done thing(redirected from the thing to do)
the done thing
A given behavior that is acceptable, appropriate, or correct in a particular social situation. Often used in the negative to convey the opposite. Calling on a friend when they are sick is simply the done thing. You should know better than to wear a skirt like that to a formal dinner—it is simply not the done thing! I'm so glad smoking indoors is not the done thing anymore!