[1] : The Collaborative International Dictionary of English v.0.48

sign language \sign" lang`uage\ simacn" la^ng`waslj, n.
   a form of language for communicating by use of gestures made
   by the hands, rather than by speech. it includes alphabets
   made by hand gestures, as well as proper languages formed
   from signs. among the latter is the american sign language
   asl, used by the deaf. see also dactylology.
   pjc
see also:
american sign language dactylology 

[2] : WordNet (r) 2.0

sign language
     n : language expressed by visible hand gestures syn: signing
see also:
signing 

[3] : Moby Thesaurus II by Grady Ward, 1.0

26 moby thesaurus words for "sign language":
   bearing, beck, beckon, body language, carriage, charade, chironomy,
   dactylology, deaf-and-dumb alphabet, dumb show, finger alphabet,
   gesticulation, gesture, gesture language, hand signal, kinesics,
   manual alphabet, motion, movement, oral method, pantomime, poise,
   pose, posture, shrug, stance

Dead Language >> D Words
Dead Language, definition of term: Dead Language
dead+language_pag1.html

Celtic Language >> C Words
Celtic Language, definition of term: Celtic Language
celtic+language_pag1.html

Body Language >> B Words
Body Language, definition of term: Body Language
body+language_pag1.html

At Sign >> A Words
At Sign, definition of term: At Sign
at+sign_pag1.html

American Sign L >> A Words
American Sign L, definition of term: American Sign L
american+sign+l_pag1.html