The Collaborative International Dictionary of English v.0.48:

Cacophonic \Cac`o*phon"ic\, Cacophonical \Cac`o*phon"ic*al\,
Cacophonous \Ca*coph"o*nous\, Cacophonious \Cac`o*pho"ni*ous\,
   a.
   Harsh-sounding.
   [1913 Webster]