What does root word mean?

A word that has no prefixes or suffixes

Explanation:

"comfort" would be an example, if you add a prefix and suffix. "uncomfortable" it's no longer a root word.

A root word has no prefix or suffix

Explanation:

- it's the most basic part of a word ... It's what's left after you remove all the affixes - the prefixes like "un-" or "anti-" and suffixes such as "-able" and "-tion." With a word like "lovely," when you take away the suffix "-ly," you're left with the root word "love."