Formal:
* Permit: This is a very formal synonym, often used in legal contexts.
* Authorize: Similar to "permit," this word implies official permission.
* Sanction: This word suggests official approval.
* Enable: This implies making something possible.
* Grant: This word often indicates permission to do something specific.
* Concede: This implies reluctantly giving permission.
Informal:
* Let: This is a more casual way to say "allow."
* Give permission: This is a straightforward phrase.
* Permit: This is a more casual synonym of "permit."
* Approve: This implies agreement with something.
* Tolerate: This implies acceptance of something, even if you don't like it.
Specific contexts:
* Admit: To allow someone to enter a place.
* Accede to: To agree to a request or demand.
The best synonym to use depends on the context and desired tone.