I was watching the movie "In the Line of Fire" (1993) with Clint Eastwood and Rene Russo. In one of the scenes, Russo tells Eastwood, "you were looking a little pea-ked out there", meaning tired/fatigued/physically overwhelmed.
That's the only usage I've found of the term, and Google lists this as a North American usage. Where did it come from, and why is it pronounced that way?