blaspheme (verb) - to speak irreverently or scornfully about sacred things; to say something offensive or slanderous [blas-feem]
BREAKDOWN: BLAS- (harm) + PHEM- (speech)
blasphemy is an act or utterance that shows disrespect or contempt for something sacred
blasphemous means irreverent, profane, or sacrilegious
Also see: euphemism
"All great truths begin as blasphemies." —George Bernard Shaw
Other than "blast," I can't think of other "blas-" words... Hmmm... Can you?