If "pronounce" means to speak or say something clearly, then the opposite could be:
* Mumble: Speak in a low, unclear voice
* Whisper: Speak very quietly
* Stutter: Speak with difficulty, repeating sounds
* Hesitate: Pause or delay before speaking
* Suppress: Hold back from speaking
If "pronounce" means to declare officially, then the opposite could be:
* Withhold: To keep back, not reveal
* Deny: To state that something is not true
* Reject: To refuse to accept
* Disapprove: To express disapproval
* Recant: To withdraw a previous statement
If "pronounce" means to identify or recognize the sound of a word, then the opposite could be:
* Mispronounce: To say a word incorrectly
* Confuse: To mistake one sound for another
* Misinterpret: To understand something incorrectly
To find the most accurate opposite, you need to consider the specific context in which "pronounce" is used.