uggo Share definition Flag An extremely ugly person. This term is used when you are too lazy to say "extremely ugly person", so, alas, uggo was created. A: My dog is frightened of me.. B: That's 'cause you're an uggo. A: Your Mom! uggo by Bunifa Latifah Halifa Sharifah Jackson September 5, 2003 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