The sign for "rude" is done by holding out the
non-dominant flat hand, palm up. The dominant hand is in a
"25"-handshape (which is a "5"-handshape with the middle finger
extended at the knuckle). Slide the tip of the dominant hand middle
finger forward over the length of the non-dominant palm.
RUDE:



Animation: RUDE

Note:
If you do the sign RUDE with the non-dominant hand palm down, it
instead means "naked/empty/available."
Memory aid: "It is rude to go to class naked."
(Which I have yet to do mind you. I'm just saying.)
You can learn American
Sign
Language (ASL) online at American Sign Language University ™
ASL resources
by Lifeprint.com © Dr. William Vicars