General prefixes:
* Mis-: This prefix generally indicates a mistake or error. You could use "mispronounced" to mean "pronounced incorrectly".
* Mal-: This prefix can also indicate a bad or wrong result, similar to "mis-". You might use "malpronounced" for a very egregious pronunciation error.
More specific prefixes:
* Pseudo-: This means "false" or "fake". You could use "pseudopronunciation" to refer to a pronunciation that sounds like a real word but isn't actually correct.
* In-: This prefix can be used for negation. You could use "inpronounced" to mean "not pronounced" at all, although this is not very common usage.
Alternative options:
* Incorrectly pronounced: This is the most straightforward and clear option.
* Improperly pronounced: Similar to "incorrectly pronounced" but implies a violation of a standard or rule.
Ultimately, the best choice depends on the specific context and the desired level of formality.