Real Dictionary

duff
adjective: If you describe something as duff, you mean it is useless, broken, or of poor quality.

duff in American English 1
a thick flour pudding boiled in a cloth bag or steamed, often containing dried fruit
noun: the buttocks or rump

duff in American English 2
the buttocks
noun: a stiff flour pudding, boiled or steamed and often flavored with currants, citron, and spices

duff in American English 3
of poor quality; inferior; worthless
transitive verb: to give a deliberately deceptive appearance to; misrepresent; fake

duff in American English 4
noun: organic matter in various stages of decomposition on the floor of the forest

duff in British English 1
noun: a thick flour pudding, often flavoured with currants, citron, etc, and boiled in a cloth bag

duff in British English 2
to change the appearance of or give a false appearance to (old or stolen goods); fake
adjective: bad or useless, as by not working out or operating correctly; dud

duff in British English 3
noun: the rump or buttocks