Lightbulb Share definition Flag Word used to describe an inbred child that has a massive forehead. That Drew kid is so creepy with his massive forehead. It looks like a 'lightbulb'. Lightbulb by Drew is an inbred child November 9, 2010 Words you can keep railfan mug chonk mug chud mug based mug 67 mug slime mug mogging mug chopped mug thot mug glazing mug huzz mug yams mug larp mug unc mug cracked mug simp mug baddie mug bop mug lolcow mug