late 14c., from Latin pecuniosus "abounding in money," from pecunia "money" (see pecuniary). Related: Pecuniously; pecuniousness.
Online Etymology Dictionary, © 2010 Douglas Harper
Examples from the Web for pecunious
If we was buried to-morrow they'd mark him 'Pecunious' and me 'Impecunious.'The Jimmyjohn Boss and Other Stories
This hunting after pecunious strangers is so systematically carried on that it might be dignified by the name of a science.