Do you know ghouls from goblins and ghosts?
"U.S. Marine," 1914, Navy slang, from leather + neck (n.). So called for the leather collars of their early uniforms; earlier in British use (1890) as a sailor's term for a soldier.
A US Marine; gyrene
[1914+ Navy; fr the leather collars of their early uniforms; the term is found by 1890 as British sailors' name for a soldier]