Part of speech: Adjective
characterized by errors; not agreeing with a model or not following established rules; the wrong side of the road"
Example: he submitted a faulty report; an incorrect transcription
Faulty, Defective, Incorrect, Wrong
fault – A related word in the same word family.
y – A related word in the same word family.
Some English words are 'fossil words'—they only survive in idioms or fixed phrases.