1. superlative form of gash; most gash (British slang: excellent, impressive, or cool)
Usage: informal; British slang; primarily used in youth or casual speech

Examples

• That's the gashest skateboard trick I've ever seen.
• He pulled off the gashest move in the entire competition.
• That concert was absolutely gashest!
• She's got the gashest style of anyone in our year.
• The gashest part of the film was the final scene.