To retrace means to go back over a path you've already traveled, or to review steps you've already taken. If you realize you dropped your house key somewhere between school and home, you might retrace your steps by walking the same route backward, carefully looking at the ground where you walked before.

When detectives retrace a suspect's movements, they're following the same route to understand what happened. When you retrace your thinking on a math problem, you go back through each step to find where you made a mistake.

You can retrace physical paths, like when a hiker retraces their trail to find a lost water bottle. You can also retrace mental paths: a scientist might retrace the logic of an experiment, or you might retrace the plot of a book to remember an important detail.

The idea of retracing suggests careful attention to what came before. You're not just going backward randomly; you're deliberately following the same route or sequence, usually because you're looking for something specific or trying to understand how you got where you are.