Here's how:
Synonym:
* Permit: "Allow" and "permit" are very close in meaning, both indicating giving permission for something.
* Let: "Allow" and "let" are often interchangeable, meaning to give permission or make something possible.
Antonym:
* Prohibit: This word means to forbid something, which is the opposite of allowing it.
* Deny: This word means to refuse to give something, which is the opposite of allowing it.
Example:
* Synonym: "The teacher allowed the students to leave early." ("Permitted" could be used in place of "allowed.")
* Antonym: "The doctor prohibited the patient from eating sugary foods." ("Denied" could also be used here.)
Therefore, "allow" can be a synonym or an antonym depending on the specific word it's being compared to.