1. A hooded garment, typically worn by monks.
2. The hood of such a garment.
3. Part of a garment that is draped to resemble a hood.
EX. The most iconic part of Batman's costume, which in itself is an ever-evolving classic that has a special place in popular art, is the cowl. Constructed of a hood, with two pointed ears on top, and a mask that hangs down over his face to his nose. Typically, at least in more recent comics and adaptation, the Dark Knight had smeared the same kind of eye-black that football players wear under their eyes to cut down on reflection of the sun. This helps to make his eyes pop out of the mask. In other version of the mask, Batman's eyes are completely obscured, or they are drawn as white space in the eyes holes.
Much like Superman's identity, which is covered by several different explanations that can be read in the link below, Batman's identity is protected by a small suspension of reality. It would make sense that a billionaire playboy would be easily recognizable...
WORD OF THE DAY! 12/9/11. Facade.