To impose means to force something on someone, often when they don't want it or didn't ask for it. When a teacher imposes a strict new rule about homework, students must follow it whether they like it or not. When a country imposes taxes, citizens have to pay them. When you impose your opinion on others during a group project, you're insisting everyone do things your way without considering their ideas.

The word carries a sense of burden or unwelcome pressure. If you visit a friend's house and stay for dinner, you might worry about imposing on their family: you don't want to be a burden or create extra work for them. Parents might say “I don't want to impose” when declining an invitation, meaning they don't want to cause trouble or inconvenience.

Something imposing (used as an adjective) means large and impressive in a way that commands attention or respect. An imposing castle towers over the landscape. An imposing figure might be someone tall and powerful-looking who naturally draws everyone's gaze.