duff

adj. not working correctly or of very poor quality.

adj. defective, useless, or of inferior quality. This usage is highly characteristic of British colloquial speech.

“I bought a second-hand phone, but it turned out to be duff and won't even turn on.”

“He spent the entire afternoon trying to repair the engine, only to realise he had been sold a duff alternator by the local scrap yard.”

British English · Informal

n. a person's bottom or backside.

n. the buttocks. This term is generally considered mild and is often used in the phrase 'get off your duff' to encourage someone to be active.

“If you want to finish this project on time, you need to get off your duff and start working.”

“The coach shouted at the players to get off their duffs and complete the final set of drills before the sun went down.”

American English · Slang

n. the layer of dead leaves and plants on the ground in a forest.

n. the layer of partially decomposed organic matter, such as leaves and twigs, located on the forest floor above the mineral soil.

“The fire spread quickly because the dry duff on the forest floor caught fire easily.”

“Ecologists measured the depth of the duff to determine how much carbon was stored in the forest's upper organic layer.”

Technical

v. to hit the ground instead of the ball in a game like golf.

v. to mishit a ball, particularly in golf, by striking the ground behind it. This is typically used as a transitive verb.

“He was so nervous on the first hole that he duffed his shot and the ball barely moved.”

“Despite his professional standing, the golfer duffed his opening drive, sending a large clod of turf flying further than the ball itself.”

Informal