Definition of "gatekeeper" []

• One that is in charge of passage through a gate. (noun)
• One who monitors or oversees the actions of others. (noun)
• A primary-care provider, often in the setting of a managed-care organization, who coordinates patient care and provides referrals to specialists, hospitals, laboratories, and other medical services. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Learning, I realized, Alexander was what I call a gatekeeper school."
• "For wounded civilians at a U.S. military hospital in Afghanistan, the gatekeeper is God."
• "The gatekeeper is the retweeter, who takes a look at the tweet and within seconds decides its value."