1. to snarl or growl, especially of a dog or other animal
Usage: informal; often used to describe aggressive animal sounds
2. to perform well or impressively, especially in extreme sports or challenging situations
Usage: slang; primarily used in skateboarding, surfing, and snowboarding communities

Examples

• The dog gnars at strangers who approach the fence.
• The skateboarder gnars down the rail with perfect technique.
• The surfer gnars through the massive waves.
• The old engine gnars and sputters before starting.
• He gnars his teeth in frustration.
• The snowboarder gnars the halfpipe like a pro.