The first reason not to say this word is that you'll end up spraying spit all over everybody.
It is also much much too pompous to use unless you are hugely fat, ruddy-cheeked, ancient, wearing a watch-chain, bald apart from a scanty comb-over, and are hated by everybody anyway.
The rhymth of the word, with its stress on the first of four syllables, will probably tear a nasty hole in the fabric of your English, too.
So, please, follow my example and don't use it today.
Word Not To Use Today: *x*c**bl*. This unmentionable word comes from the Latin word exsecrārī, to curse, from sacer, which means sacred.