A blockage is something that stops or prevents movement or flow. When leaves clog a rain gutter, they create a blockage that stops water from draining properly. When a toy gets stuck in a pipe, it forms a blockage. In your body, a blockage in an artery can prevent blood from flowing where it needs to go, which doctors take very seriously.

The word applies to physical obstacles, like a fallen tree creating a road blockage, but also to less tangible things. A student might experience a mental blockage when they know the answer to a test question but can't quite remember it: the information is stuck, blocked from coming forward. Writers talk about having a blockage when ideas won't flow onto the page.

Notice that a blockage usually means something is stuck in a space where things should normally move through freely. Water should flow through pipes, traffic should move along roads, and ideas should flow from your mind. When something interrupts that natural flow, you've got a blockage. Fixing a blockage often means finding what's stuck and clearing it away so things can move again.