Slang. a person who is the best or one of the best in a particular field; the top-ranked person in a group.
an ace fighter pilot.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for top gun
The men toured the Fallon U.S. Naval Air Station in Nevada, where the real Top-Gun pilots train.Antidepressant, Sleep Aid Found in Director Tony Scott’s Body|Christine Pelisek|October 22, 2012|DAILY BEAST