Alex mentions: My favorite sign language word is the sign for "b*llsh*t," as depicted in the film "Children of a Lesser God," but it is hard to describe.

Lessee kin I give it a try:

One arm held in front of body with the forearm horizontal across the body at about mid chest level hand in a fist palm down with fore and little fingers extended; representing the horns of the bull. Other arm immediately below first arm in the same configuration with the fist of the latter under the elbow of the former and the elbow of the latter under the fist of the former. The fingers are not initially extended. Rapidly open fist of lower hand; representing the stercorem of the bull. Contemptuous sneer on face. Mouth "Yeah, right" or words to that effect.