Skinnies are defined as millita forces hailing from an impovished nation
Was originaly used to describe people in Somallia in "Black Hawk Down" but has also extended to other regions of conflict.
Also used in Multiplayer Games, such as Command and Conquer: Generals, to describe the Terrorist teams
"Skinnies, comming into the left-hand side of your base!"
"Don't worry, Pathfinders have them pinned."