A member of the US Marine Corp. the term "Leatherneck" was derived from a leather stock once worn around the neck by both American and British Marines—and soldiers also. Beginning in 1798, "one stock of black leather and clasp" was issued to each U. S. Marine annually.
An exclamation of "hell yes!" That feeling you get when something amazing dances into your world. It's a combination of yay + yes = yas! Sometimes spelled, yasss! The more "s" on the end the more fun you are having.