A gremlin is a mischievous imaginary creature that people blame for causing mysterious problems or malfunctions, especially with machines. During World War II, British pilots jokingly blamed gremlins when their planes developed strange mechanical issues they couldn't explain. The idea caught on: if your engine sputtered for no clear reason, a gremlin must have tampered with it.

Today, people still talk about gremlins when technology acts up in puzzling ways. When your computer freezes right before you save your work, you might say “there's a gremlin in my computer.” When the printer jams for the third time even though you've done everything right, gremlins get the blame. It's a playful way to express frustration with unexplainable glitches.

The word also appears in the 1984 movie Gremlins, where cute creatures transform into chaotic monsters. But in everyday conversation, a gremlin is simply whatever mysterious force seems to be sabotaging your technology. Blaming the gremlins is more fun than saying “something's broken and I don't know why,” and it captures that feeling when machines seem to have minds of their own.