Preoperative is a term commonly used in medical field that refers to a period before an operation. It is a condition that many people experience before undergoing any surgical procedure. On the other hand, there are several antonyms for the word preoperative that denote the opposite of it. These words are postoperative, which is the period after an operation, intraoperative, which is the period during the operation, and nonoperative, which means a condition where a patient does not require any surgical intervention. These antonyms are often used interchangeably by medical professionals to describe different states of a patient's medical condition depending on the circumstance.