butter bar

• butterbar

Derived from the insignia of an O-1 in the US Military, which consists of a single yellow bar.

butter bar (plural butter bars)

1. (US Air Force, US Army, US Marines, slang) A second lieutenant.
2. (US Navy, US Coast Guard, slang) An ensign.

• 1977, Rafael Alberto Rivas, Survival: my life in love and war, page 154:

  "Hey, 'Butter Bar,' " one of the brothers called, referring to the lieutenant, "how much ya want for that round-eyed whore ya got?"

• 2010 -- Green Zone Dir. Paul Greenglass. Perf. Matt Damon. Dist. Universal Pictures.

  "The 101st sent 35 men and one butter bar in here and they don't even have this place secure."