1. a person who controls access to something or someone
2. a person employed to guard a gate and control who may pass through it

Examples

• The secretary acted as a gatekeeper, screening all visitors before they could meet the CEO.
• The old gatekeeper checked our identification before allowing us into the estate.
• Publishers serve as gatekeepers in the literary world, deciding which books get published.
• The security guard was the gatekeeper for the exclusive club.
• She became the gatekeeper of family traditions, deciding which customs to preserve.
• The gatekeeper at the university entrance directed students to the proper buildings.