(idiomatic, ironic) Don't overexert yourself (in doing something that does not require much effort).

(idiomatic, informal) Do not broach that topic.

(idiomatic, humorous) Alternative form of been there, done that, bought the T-shirt.

(idiomatic, humorous) Expresses the speaker's complete familiarity with a situation, with overtones of cynicism or exhaustion.

A water-heating system for domestic use, consisting of a drum of water mounted above a fire.

A surname from Irish, Alternative spelling of Danaher

One should not depend upon a favorable (and typically overoptimistic) outcome to one's plans until it is certain to occur.

plural of don't

A phrase used in response to a question or command in which the target person does not know the answer to or how to respond.

You cannot accurately judge a person solely by appearances.