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

jackstone \jack"stone`\, n.
   1. one of the pebbles or pieces used in the game of
      jackstones.
      1913 webster

   2. pl. a game played with five small stones or pieces of
      metal. see 6th chuck. also called jacks. see
      jack12, n.
      1913 webster
see also:
chuck jacks jack 

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

carangid \carangid\ n.
   any fish of the family carangidae, including the
   cavallas, jacks, pompanos and scads.
   wordnet 1.5
see also:
carangidae cavallas jacks pompanos scads 

[3] : WordNet (r) 2.0

jacks
     n 1: plaything consisting of small 6-pointed metal pieces that
          are used along with a ball to play the game of jacks
          syn: jackstones
     2: a game in which jackstones are thrown and picked up in
        various groups between bounces of a small rubber ball
        syn: jackstones, knucklebones
see also:
jackstones knucklebones 

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

44 moby thesaurus words for "jacks":
   agate, ball, baseball bat, bat, battledore, bauble, blocks,
   checkerboard, chessboard, club, cockhorse, cricket bat, cue, doll,
   doll carriage, gewgaw, gimcrack, golf club, hobbyhorse,
   jack-in-the-box, jackstones, jackstraws, kickshaw, knickknack,
   marble, marionette, mig, paper doll, pick-up sticks, pinwheel,
   plaything, puppet, racket, rag doll, rocking horse, sport, steelie,
   taw, teetotum, top, toy, toy soldier, trinket, whim-wham

Jacks >> J Words
Jacks, definition of term: Jacks
jacks_pag1.html