The Collaborative International Dictionary of English v.0.48:

Smash \Smash\ (sm[a^]sh), v. t. [imp. & p. p. Smashed
   (sm[a^]sht); p. pr. & vb. n. Smashing.] [Cf. Sw. smisk a
   blow, stroke, smiska to strike, dial. Sw. smaske to kiss with
   a noise, and E. smack a loud kiss, a slap.]
   1. To break in pieces by violence; to dash to pieces; to
      crush.
      [1913 Webster]

            Here everything is broken and smashed to pieces.
                                                  --Burke.
      [1913 Webster]

   2. (Lawn Tennis) To hit (the ball) from above the level of
      the net with a very hard overhand stroke.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

smashing
    adj 1: very good; "he did a bully job"; "a neat sports car";
           "had a great time at the party"; "you look simply
           smashing" [syn: bang-up, bully, corking,
           cracking, dandy, great, groovy, keen, neat,
           nifty, not bad(p), peachy, slap-up, swell,
           smashing]
    n 1: the act of breaking something into small pieces [syn:
         smashing, shattering]

Moby Thesaurus II by Grady Ward, 1.0:

177 Moby Thesaurus words for "smashing":
   OK, Smyth sewing, abrasion, ace-high, appulse, atomization,
   attrition, backing, bad, bang-up, beating, bibliopegy,
   binder board, binding, bonzer, book cloth, book cover, book jacket,
   bookbinding, bookcase, boss, brecciation, brunt, bulldozing,
   bulling, bully, bump, but good, cannon, carambole, carom, case,
   casemaking, casing-in, censorship, clash, collating,
   collating mark, collision, comminution, concussion, concussive,
   cool, corking, cover, crack-up, crackdown, crackerjack, crash,
   crashing, crumbling, crump, crunch, crushing, dandy, delicious,
   demolishment, demolition, detrition, disassembly, disintegration,
   dismantlement, ducky, dust cover, dust jacket, encounter,
   extinguishment, fab, fine and dandy, flattening, folding, footband,
   fragmentation, gathering, gear, gluing-off, granulation,
   granulization, grating, great, grinding, groovy, hammering,
   hard binding, headband, heavy, hot, hunky-dory, impact,
   impingement, jacket, jam-up, just dandy, keen, leveling,
   levigation, library binding, lining, lining-up, marvy, mashing,
   mauling, mean, mechanical binding, meeting, neat, nifty,
   niggerhead, nobby, okay, onslaught, out of sight, peachy,
   peachy-keen, percussion, percussive, perfect binding,
   plastic binding, pounding, powdering, putting down, quashing,
   quelling, quenching, ramming, razing, repression, ripping,
   rounding, rum, saddle stitching, scrumptious, sewing, shock,
   shredding, side sewing, sideswipe, signature, slap-up,
   sledgehammering, slipcase, slipcover, smash, smash-up, smothering,
   soft binding, solid, something else, spiffing, spiffy,
   spiral binding, squashing, squelching, stamping, stapling,
   stifling, strangling, stunning, subdual, suffocating, suppression,
   swell, tailband, tearing down, throttling, thrusting, tipping,
   tough, trimming, trituration, unmaking, whomp, wire stitching,
   wizard, wrapper, wreckage, wrecking