greenie beanie; green beanie noun a member of the US Army Special Forces US An extension of the more common green beret.
Those Green Beanie guys are overrated. Too lazy to work, too nervous to steal. — Elaine Shepard, TheDoomPussy, p. 46, 1967
There went the good advisors / And some “Greenie Beanies” too / To save the little country / For the likes of Madame Nhu! — Thomas Bowen, TheLongestYear, p. 22, 1990: “Ghost Advisors By and By”