Gassy Man and the other one who made those erroneous markings in brackets [didn't bother to remember your nick]:
An ad hominem attack seems to be whatever you guys think it is, not what it really is, an attack on the personal attributes of the arguer in lieu of a real response to the argument. You two believe the ad hom attack not only involves the person, but what the person has done in the past, especially if it has value in assessing what the person is saying today.
Under your definitions, if I refuse to believe you because you have told repeated lies in the past, I am attacking you personally. If I say your repeated use of "logical fallacy" identification to shame people makes you look petty, I'm committing an ad hominem. I have judged you based on your past actions and I'm not to do it.
So if I'm to act logically, I can't consider your past actions or statements. That's an ad hominem. I'm to be used as an example in these classes if I describe my thinking on bellgab.
Seriously, look up the definition. Then read it. Then read it again and again until you get it (or don't). Maybe take a college class in it.
So, here's an example: The fact that someone lied 99 times does not mean that they lied the 100th time. It would be illogical to conclude that. Instead, you would want to prove they are lying -- in other words, deal with what they are saying and not them. If you simply attack them by calling them a liar without knowing that they lied, you attacked the person, not what they said. That's an ad hominem attack.
You can decide whether or not you believe
someone is credible based on reputation, but even that is a weak argument, and it does not prove logically that they are doing anything presently. It is all about your belief, or prejudice, not about logic.
Here's an even better example: In quite a few places on social media, people are saying Art is a liar and manipulative "drama queen" because he has pulled stunts like this five or more times before. Therefore, what he claims now must also be a lie because, by definition, he's a liar. That's an ad hominem attack. Art could well be telling the truth regardless of anything he's done int he past. The way to determine this is to determine the veracity of the claim -- and not simply to dismiss the claim because people say Art is a liar.