The sign for suitcase looks like you are holding on to the handle of
a suitcase and hefting it (a bit) twice.
Note: This sign can also be used to mean briefcase or "purse"
(as in handbag). If you need to distinguish between the two
you could modify the location and movement for "suitcase" to be
lower and to look as if you are holding something heavier.
SUITCASE (animated gif)
Also see: BAG
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American Sign Language (ASL) online at American Sign Language University ™
ASL resources by Lifeprint.com © Dr. William Vicars