Untimely means happening at a bad time or too soon, especially when something ends earlier than it should. When we say someone suffered an untimely death, we mean they died too young or unexpectedly, before they should have. A promising scientist who dies in an accident at age 35, or a healthy athlete who dies suddenly, experiences an untimely death.

The word can describe other unfortunate timing too. An untimely interruption might ruin an important moment, like when the fire alarm goes off right as your teacher is explaining the key point of a lesson. An untimely injury could end an athlete's season just before the championship game.

Something untimely is badly timed in a way that causes problems or sadness. The opposite would be timely, meaning well-timed or happening at the right moment. When a doctor makes a timely diagnosis, catching a disease early, that's good timing. An untimely diagnosis would come too late to help.