The Collaborative International Dictionary of English v.0.48:

Detonate \Det"o*nate\, v. i. [imp. & p. p. Detonated; p. pr. &
   vb. n. Detonating.] [L. detonare, v. i., to thunder down;
   de + tonare to thunder; akin to E. thunder. See Thunder,
   and cf. Detonize.]
   To explode with a sudden report; as, niter detonates with
   sulphur.
   [1913 Webster]