Short guys or girls who hang together, thereby making themselves feel collectively bigger and more powerful. Runt posses can make normal-sized people feel freakishly tall.
Warning: Male runt posses can turn into the most obnoxious guys in the room.
Liz: "Look, Jan and Katie just got here? Let's go say hi!"
Gwen: "Naw, girl, they're with Squeaky and Lil' Jeanie. I'll look like Andre the Giant next to them. Total runt posse."
Pat: "Man, did you see that little dude over there just get in my face because I accidentally grazed his left elbow?!"
Pete: "Bro, that's just Timmy Smalls feelin' like a bamf cause he's hanging with his Runt Posse. I'd stay away from him though."