The Collaborative International Dictionary of English v.0.48:

Detonation \Det`o*na"tion\ (d[e^]t`[-o]*n[=a]"sh[u^]n), n. [Cf.
   F. d['e]tonation.]
   An explosion or sudden report made by the instantaneous
   decomposition or combustion of unstable substances; as, the
   detonation of gun cotton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

detonation
    n 1: a violent release of energy caused by a chemical or nuclear
         reaction [syn: explosion, detonation, blowup]
    2: the act of detonating an explosive

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "detonation":
   backfire, bang, bark, blast, blowout, blowup, boom, bowshot,
   bullet, burst, cannon, crack, discharge, ejection, explosion,
   flare, flash, fulguration, fulmination, fusillade, gun, gunfire,
   gunshot, pop, potshot, report, salvo, shot, spray, stoneshot,
   tattoo, volley