The Collaborative International Dictionary of English v.0.48:

panhandle \pan"han`dle\ (p[a^]n"h[a^]n`d'l), v. i.
   To accost people in a public place and ask for money; to beg.
   -- pan"hand`ler (p[a^]n"h[a^]nd`l[~e]r), n. --
   pan"hand`ling (p[a^]n"h[a^]nd`l[i^]ng), n.
   [PJC]

WordNet (r) 3.0 (2006):

panhandler
    n 1: a beggar who approaches strangers asking for money

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "panhandler":
   beggar, bum, bummer, cadger, coupon clippers, drone, freeloader,
   hobo, idle rich, leisure class, loafer, lounge lizard,
   lumpen proletariat, mendicant, mendicant friar, mendicant order,
   moocher, nonworker, parasite, rentiers, schnorrer, scrounger, spiv,
   sponger, the unemployable, the unemployed, tramp