The Collaborative International Dictionary of English v.0.48:

Pelf \Pelf\ (p[e^]lf), n. [OE. pelfir booty, OF. pelfre, akin to
   pelfrer to plunder, and perh. to E. pillage. Cf. Pilfer.]
   Money; riches; lucre; gain; -- generally conveying the idea
   of something ill-gotten or worthless. It has no plural.
   "Mucky pelf." --Spenser. "Paltry pelf." --Burke.
   [1913 Webster]

         Can their pelf prosper, not got by valor or industry?
                                                  --Fuller.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pelf
    n 1: informal terms for money [syn: boodle, bread,
         cabbage, clams, dinero, dough, gelt, kale,
         lettuce, lolly, lucre, loot, moolah, pelf,
         scratch, shekels, simoleons, sugar, wampum]