Green’s Dictionary of Slang

tumbe n.

[Sp. tumbar, to knock down]

(US/P.R. Und.) a swindle, a confidence trick; also attrib.

[US]E. Torres Carlito’s Way 64: It could be a beat — tumbe — for twenty thou or a piece of ass, all the same to Nacho.
[US]E. Torres Q&A 21: He had to whack out a few tumbe artists.