Answer: evil, bad.
Explanation: A root word it's the most basic part of a word. It's what's left after you remove all the affixes (the prefixes and suffixes). The given words "malady," "malicious," and "malignant" share the root "mal" which is a latin root word that means "bad" or "evil," as we can see, the given words have negative connotations, malady is a disease, malicious is something intended to do harm, and malignant means evil in nature or effect.
