o•ver•pro•nounce
Pronunciation: (ō"vur-pru-nouns'), [key] — v., -nounced, -nounc•ing.
—v.t. - to pronounce (a word, syllable, etc.) in an exaggerated, affected, or excessively careful manner.
—v.i. - to pronounce or speak overcarefully, affectedly, exaggeratedly, etc.: When he overpronounces that way, he seems to be patronizing his audience.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.