Answer:
The affix "ous" indicates the following about the word "joyous":
It is an adjective which derives from the noun "joy".
Explanation:
Whenever we add the affix "ous" to a noun, it becomes an adjective. We are not talking about any nouns, but abstract ones only, such as "fame", "adventure", "anonymity", "generosity", "jealousy", "disaster", "hazard", etc. Therefore, by adding the suffix "ous" (affixes: prefixes and suffixes) to the abstract noun "joy", it becomes an adjective which means that person or thing we are talking about is characterized by joy.
