adverb
1. in a way that is directed against a person rather than the position they are maintaining.
2. marked by or being an attack on an opponent’s character rather than by an answer to the contentions made.
“…made an ad hominem personal attack on his rival.”
adjective
1. directed against a person rather than the position they are maintaining.
2. appealing to feelings or prejudices rather than intellect. “vicious ad hominem attacks”