- an armed plainclothes federal marshal riding on an airliner to protect against skyjacking.
Origin of sky marshal
An Americanism dating back to 1965–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- an armed security guard on a commercial aircraft
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012