'To pop up the spout' definitions:

Definition of 'To pop up the spout'

From: GCIDE

Spout \Spout\, n. [Cf. Sw. spruta a squirt, a syringe. See Spout, v. t.]
1. That through which anything spouts; a discharging lip, pipe, or orifice; a tube, pipe, or conductor of any kind through which a liquid is poured, or by which it is conveyed in a stream from one place to another; as, the spout of a teapot; a spout for conducting water from the roof of a building. --Addison. "A conduit with three issuing spouts." --Shak. [1913 Webster]
In whales . . . an ejection thereof [water] is contrived by a fistula, or spout, at the head. --Sir T. Browne. [1913 Webster]
From silver spouts the grateful liquors glide. --Pope. [1913 Webster]
2. A trough for conducting grain, flour, etc., into a receptacle. [1913 Webster]
3. A discharge or jet of water or other liquid, esp. when rising in a column; also, a waterspout. [1913 Webster]
To put up the spout, To shove up the spout, or {To pop up the spout}, to pawn or pledge at a pawnbroker's; -- in allusion to the spout up which the pawnbroker sent the ticketed articles. [Cant] [1913 Webster]