Permission to enter is a term used to describe the authorization or allowance of someone to enter a certain place. ADMITTANCE (10 letters) is a synonym for permission to enter, and it implies that the person is allowed to stay in the place for an extended period of time. ADMISSION (9 letters) is also a synonym for permission to enter, but it implies that the person is only allowed to enter the place for a short period of time. ACCESS (6 letters) is another synonym for permission to enter, and it implies that the person is allowed to enter the place without any restrictions.