There are insults and there are ad hominens…
For many people on the Internet not actually versed in Philosophy, they tend to confuse the two. Maybe this stems from wishing to appear clever, maybe they have just picked up the phrase from another person ignorant of the origin of the phrase.
If you want to talk about an insult, then there is a perfectly good set of words (see below) that mean insult, “insult” for example.
Ad hominem, on the other hand, is not an insult. It is a short form of argumentum ad hominem , which is an argument made ‘against the man’, rather than against the argument. As such it is not an insult but an informal fallacy.
For example: The chancellor is wrong to cut spending because we need to stimulate the economy, and it is wrong because he went to Eton College.
The first part of the reason is valid as it might actually be a reason the chancellor is wrong. The second part descends into irrelevance as his schooling does nor bear on the topic of fiscal stimulus. Such a statement is likely to be designed to rally support from those that think the Chancellor is a stuck up toff, but has nothing to do with any economic argument.
If I call the Chancellor a stuck-up toff, that is an insult. I am right about that, but that is not an argument about the validity of his budget.
I’m sure when the Labour Party next have a Chancellor he also will most likely be an upper-class toff too.
But these are insults, not ad hominems.
I call then “INSULTS” so that when I use “ad hominem” it is reserved for a species of fallacy that is a useful thing to identify in a philosophical argument.
There are many other words you can use for insults, but ad hominem is not among them:
abuse, affront, cheap shot, contempt, contumely, derision, despite, discourtesy, disdainfulness, disrespect, ignominy, impertinence, impudence, incivility, insolence, invective, libel, mockery, obloquy, offense, opprobrium, put-down, rudeness, scorn, scurrility, shame, slander, slight, snub, superciliousness, taunt, unpleasantry, vilification, vituperation.