persp, n. — Green’s Dictionary of Slang

persp n.

[abbr.; all uses in the works of P.G. Wodehouse (1881–1975)]

perspiration.

1923		Wodehouse Inimitable Jeeves 24: The good old persp. was bedewing my forehead by this time in a pretty lavish manner.
1966		Wodehouse Plum Pie 19: It was with quite a few beads of persp bedewing the brow that I went back to the dining room.
1974		Wodehouse Aunts aren’t Gentlemen 12: He said ‘Phew’ and removed a bead of persp. from the brow.