Other forms: yelled; yells
To yell is to call or cry out loudly. You might yell across a loud cafeteria to get your friend's attention, or yell at your sister for borrowing your favorite sweater.
Use the word yell as a verb or noun to describe the noise someone makes when they holler or shout. You can yell with enthusiasm, the way a crowd at a sporting event does, or in anger, like an irate driver yelling out the car window. A yell can express surprise, fury, or delight — but it's always loud. The Old English root is galan, "to sing."