Hugh Hefner -- So So Def! 1 9/3/2008 6:03 PM PDT BY TMZ STAFF Def -- adj. -- to describe a person, thing, or event that is cool. "Yo dawg, Hugh Hefner brought like 5 hot blonde skeezers out clubbin' in Hollywood last night -- that dude is def." Oh, he also can't hear very well anymore. See Also "Girl Next Door" Lookin' to Score?