What is an ad hominem for dummies? plz give an example.

"(of an argument or reaction) directed against a person rather than the position they are maintaining."
- Google's Dictionary
Basically when someone has a statement opposing the other person in the argument.

This is where you would be attacked by a persons character, rather than by the answer of the argument. 
Example - "You failed third grade so your answer is invalid." or "you cant go to law school because your dad is a criminal"

Syllable added to a root word to change its meaning : affixan independent word--example run,walk,book : free morphemeaffix that gives grammatical meaning such as tense or number : inflectiona word part that must attach to a word in order to be usable : bound morphemedegree of comparison formed by adding -er or more to an adjective : comparativedegree of comparison formed by adding -est or most to an adjective : superlativeaffix added to the beginning of a word : prefixaffix added to the end of a word : suffixroot word of lovable : lovetwo roots used together to form one word : combining form