A smirk is a smile that suggests smugness, superiority, or secret amusement rather than genuine happiness or friendliness. When someone smirks, one corner of their mouth turns up in a knowing way that can feel irritating to others.

Picture a student who finishes a difficult test early and smirks at classmates still working, silently broadcasting, “this was easy for me.” Or imagine someone who knows a secret smirking while others try to figure out what happened. The expression says, “I know something you don't” or “I'm better than you think.”

A smirk differs from a regular smile in its effect on others. A genuine smile invites people in and makes them feel good. A smirk pushes people away and can make them feel small or excluded. Someone might smirk after winning an argument, catching someone in a mistake, or hearing gossip about a rival.

The word often appears in stories to show that a character feels superior or is up to something sneaky. When a villain smirks in a movie, audiences immediately recognize that expression of self-satisfied confidence.