What Makes Up the Name: voluptuous + lumpy or voluminous + sumptuous
Sometimes portmanteaus happen by accident when your roommate is trying to say "voluptuous" and sound all smart-in-the-brain and then he mixes a "lump" in there: "volumptuous". The problem with these inadvertent ones is that no one really knows what they mean. Is it a lumpy voluptuousness? A massive luxuriousness? Are we talking about a woman or a couch or are you just stupid? Be careful with this one, because it often just means "fat" so you should make sure they sext you a picture first.
Origin: The Urban Dictionary lists it's first posting in March 2006, but some dumbass definitely said it before that.