Worthless; not working properly, defective.
Why do I always get a shopping trolley with duff wheels?
An incompetent or clumsy person.
A player having little skill, especially a golfer who duffs.
A pedlar or hawker, especially one selling cheap or substandard goods.
Cheap or substandard goods sold by a duffer.
A cow that does not produce milk.
A cattle thief or thief of other livestock; one who alters the brands of cattle.
A racing pigeon that does not perform well.
Any of various nymphalid butterflies of the genus Discophora.