ad hominem

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Attacking a person's character or motivations rather than a position or argument.
• adjective Appealing to the emotions rather than to logic or reason.

from The Century Dictionary.

• noun To the man; to the interests or passions of the person.

from the GNU version of the Collaborative International Dictionary of English.

• A phrase applied to an appeal or argument addressed to the principles, interests, or passions of a man.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun logical fallacy A fallacious objection to an argument or factual claim by appealing to a characteristic or belief of the person making the argument or claim, rather than by addressing the substance of the argument or producing evidence against the claim; an attempt to argue against an opponent's idea by discrediting the opponent himself.
• noun A personal attack.
• adjective Of or relating to ad hominem.
• adverb In an ad hominem manner.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective appealing to personal considerations (rather than to fact or reason)