Definitions
1.NounA person or group who controls access to something or somebody.
2.NounA person who guards or monitors passage through a gate.
3.NounA common orange and brown butterfly with eyespots, Pyronia tithonus, of the family Nymphalidae.
4.NounIn dissociative identity disorder, an aspect of the personality that controls access to the various identities.
5.NounOne who gatekeeps.
6.NounA provider of core platform services with specific characteristics (Regulation (EU) 2022/1925 of the European Parliament and of the Council)