Pout (verb)

1. To push one's lips or one's bottom lip forward as an expression of disappointment, displeasure, or petulance.
2. To sulk or look unhappy.
3. To make a sulky face.

Origin:

The word pout likely comes from the old english word pútan, meaning "to push out.".

Examples:

1. She pouted when she realized she wouldn't be able to go to the concert.
2. He pouted for the rest of the day after he didn't get what he wanted.
3. She could tell by the way he was pouting that he was unhappy with her decision.
4. The little girl pouted her lips when her mother told her she couldn't have any candy.
5. He pouted when his boss told him he wouldn't be getting a raise this year.