name stem is not defined

As an AI language model, I can provide a definition of "stem" for you:

The stem is the part of a word that remains after removing any prefixes or suffixes. It is the core or base of the word that carries its essential meaning. For example, in the word "unhappy," the stem is "happy," and the prefix "un-" changes the meaning to indicate the opposite. Similarly, in the word "running," the stem is "run," and the suffix "-ing" indicates that the action is happening in the present continuous tense.