A knockoff is a cheap imitation of a popular product, usually made to trick people into thinking they're getting the real thing. When someone buys knockoff sneakers, they might look almost like the famous brand from a distance, but the quality is lower, the logo is slightly wrong, and they fall apart much faster than authentic shoes.

Companies that make knockoffs copy successful products without permission, trying to profit from someone else's hard work and reputation. You might see knockoff toys that look like characters from a popular movie, knockoff electronics that mimic expensive gadgets, or knockoff designer bags sold on street corners. The price seems tempting, but knockoffs are usually disappointing: the colors fade quickly, zippers break, and electronics stop working.

The word can also be used more casually to describe something that copies another thing's style, not necessarily to deceive. A teacher might say a student's story is “kind of a knockoff of The Hunger Games” if it borrows too heavily from the plot.