* Permission: This is the most common and general abstract noun for "permit," representing the act of granting consent or allowance.
* Authorization: This refers to the official act of giving permission, usually in a formal setting.
* Sanction: This emphasizes the formal approval or endorsement given, often by an authority.
* License: This specifically refers to a legal document granting permission to do something, like drive a car.
* Liberty: This refers to the freedom or right to do something, which can be considered an abstract noun related to being permitted.
The best abstract noun depends on the specific context and the nuance you want to express.