What does “aanstekelijk” mean in Dutch?

Aanstekelijk does two jobs at once. It describes a cold you can catch (een aanstekelijke ziekte) and a tune you can’t shake (een aanstekelijk liedje). Both senses come from the same root: aansteken, “to ignite or infect.” The logic is identical — something leaps from one person to another, whether through the air or through the ears. Master this word and both meanings arrive together.

The clip asks why yawning is so aanstekelijk and then dares you to stare at a yawning mouth for a full minute without yawning yourself — a live demonstration of the word. The answer the presenter offers is mirror neurons, the brain circuits “programmed to imitate the behaviour of others.” That framing also captures the catchy-song sense: a hook wires itself in through the same imitative pull. Beyond yawning, you’ll hear aanstekelijk for infectious laughter (aanstekelijk lachen), infectious enthusiasm (aanstekelijk enthousiasme), and any earworm that refuses to leave.