The word part that is added to an affix to make a new word is a suffix.
The word part that is added to an affix to make a new word is called a root. A root is the base or core part of a word that holds its meaning. It can be combined with a prefix or suffix to create a different word with a modified meaning. For example, in the word "unhappiness," the root is "happy," and the prefix "un-" is added to create a new word with the opposite meaning.
