Pretend is a verb that means to behave as if something is true when you know that it is not, especially in order to deceive people or as a game.
Common usage examples:
1. "She pretended not to see me when I walked by."
2. "The children were pretending to be pirates."
3. "Don't pretend you don't know what I'm talking about!"
Synonyms: feign, simulate, fake, make believe