Dictionary.com
definitions

rappen

[rah-puh n]
noun, plural rap·pen.
  1. a bronze coin and monetary unit of Switzerland; centime.

Origin of rappen

1830–40; < Swiss German; late Middle High German rappen a type of coin first minted in Alsace, literally, raven (a jocular reference to the eagle on the coin), declensional variant of Middle High German rappe, a by-form of raben, Old High German hraban; see raven1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018