Learn it. The Urban Dictionary has a number of defs for “derping.” 1. When you’re herping the derp by derp derping around. Usually done on the internet; 2. a) Internet slang for trolling. b) In traditional gaming jargon, engaging in a discussion that goes way outside likelihood or canon without any serious intent; 3. To derp all over oneself in a disgraceful manner; to be physically inadequate. “Now you’re just derping all over yourself.” Not entirely sure which definition this gif falls under. We’re guessing “herping the derp by derp derping around.”