The Collaborative International Dictionary of English v.0.48:

tuppence \tuppence\ n.
   1. [contraction from two pence.] A former U.K. silver coin; a
      U.K. bronze decimal coin worth two pennies.

   Syn: twopence
        [WordNet 1.5] Tupperware

WordNet (r) 3.0 (2006):

tuppence
    n 1: a former United Kingdom silver coin; United Kingdom bronze
         decimal coin worth two pennies [syn: twopence,
         tuppence]

Moby Thesaurus II by Grady Ward, 1.0:

86 Moby Thesaurus words for "tuppence":
   a continental, a curse, a damn, a darn, a hoot, bagatelle, bauble,
   bawbee, bean, bibelot, bit, brass farthing, button, cent, crown,
   curio, dollar, farce, farthing, feather, fig, fiver, fleabite,
   florin, folderol, fourpence, fourpenny, fribble, frippery, gaud,
   gewgaw, gimcrack, groat, guinea, hair, half crown, half dollar,
   halfpenny, hill of beans, jest, joke, kickshaw, knickknack,
   knickknackery, mag, meg, minikin, mite, mockery, molehill, monkey,
   new pence, np, p, pence, penny, peppercorn, picayune, pin,
   pinch of snuff, pinprick, pony, pound, quid, rap, red cent,
   row of pins, rush, shilling, shit, sixpence, snap, sneeshing, sou,
   straw, tenner, threepence, threepenny bit, thrippence, toy, trifle,
   trinket, triviality, two cents, twopence, whim-wham