Answer: stilted
Explanation: Tbh I searched the definition of “stilted”on the internet; it means “(of a manner of talking or writing) stiff and self-conscious or unnatural.” It wouldn’t be slang because slang means everyday talk. Vague means not thoroughly described. Cliché is used to describe a word, phrase, or event that is overused (ex. happily ever after, love at first sight)
