Is a predicate adjective is a word that renames the subject true or false?

False. A predicate adjective describes or modifies the subject of a sentence, typically following a linking verb, rather than renaming it. For example, in the sentence "The sky is blue," "blue" is the predicate adjective that describes the subject "the sky." Renaming the subject is the function of a predicate nominative, not a predicate adjective.