Origin of detonate; from Classical Latin detonatus, past participle of detonare, to thunder ; from de-, intensive + tonare, to thunder
intr. & tr.v.det·o·nat·ed, det·o·nat·ing, det·o·nates
Origin of detonateLatin dētonāre, dētonāt-, to thunder down : dē-, de- + tonāre, to thunder; see (s)ten&schwa;- in Indo-European roots.
(third-person singular simple present detonates, present participle detonating, simple past and past participle detonated)
From Latin detonāre. It meant "to stop thundering", e.g. as in weather (de- = "from", tonare = "to thunder"). The current English meaning seems to be a new formation in postclassical times.