A fork of Rural Dictionary
I.L.S. or Imaginary Lat Syndrome is an ailment suffered by men who walk around with thier arms further away from their lats (latimus dorsi), the muscle on the side of thier torso, to create the illusion that their lats (and physiques) are much bigger than they are.
Did you see Leah's new boyfried? The kid's got I.L.S. He think he's big but he's only like a buck fifty.
Usually ILS sufferers are guys that refuse to work out, but nonetheless hold their arms out at about a 45 degree angle from their body as if to say "hey it's hard bein' this ripped" Also called "the cobra" Often times coupled with the very popular IGS or Invisible Girdle Syndrome.