mutton dressed as lamb noun1 •(UK, offensive) A middle-aged or elderly woman dressed in a style more suited to a young woman, especially if in a deliberate attempt to appear young.Cully Barnaby: Dad, that old lady, the mutton dressed as lamb. Do you know her? DCI Tom Barnaby: That's a terrible thing to say... even though it's true. No, I don't. — 1998
