Gawd Dayum is internet slang for god damn, spelled phonetically to capture the way the phrase sounds when it is stretched out in surprise. Online, it has become a shorthand reaction for attraction, amazement and disbelief, and the extended version circulating on soundboards gives editors a longer, more dramatic take than a single shouted word. It stays popular because the reaction is instantly readable, works without context and fits almost any surprising moment in short-form video.