To sign "deny," form both hands into open-"A"-hands. What that
means is make "A" hands but stick the thumbs out.
Hold both thumbs under your chin with the pad of each thumb touching
the underside of the chin. Quickly move both hands forward.
This sign is very close to the sign for "NOT" except that the NOT
sign only uses the dominant hand.
You can learn
American Sign Language (ASL) online at American Sign Language University ™
ASL resources by Lifeprint.com © Dr. William Vicars