Answer: In the adjective "impatient," the prefix "im" means "not."
Explanation:
Im- is added to words that begin with 'm', ' p', or 'b' to form words with the opposite meaning. "Patient" begins with the letter 'p', so adding "im" to it makes it mean the opposite of patient, or "not patient." Therefore, the prefix "im" means "not" in the adjective "impatient."