The Collaborative International Dictionary of English v.0.48:

Pauper \Pau"per\, n. [L. See Poor.]
   A very poor person; one without any means of support,
   especially one dependent on private or public charity. Also
   used adjectively; as, pauper immigrants, pauper labor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pauper
    n 1: a person who is very poor

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "pauper":
   almsman, almswoman, bankrupt, beggar, break, bum, bust, casual,
   charity case, down-and-out, down-and-outer, fold up, hardcase,
   hobo, impoverish, indigent, insolvent, lazarus, mendicant,
   pauperize, penniless man, poor devil, poor man, poorling,
   starveling, tramp, vagrant, welfare client



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PAUPER. One so poor that he must be supported at the public expense.
    2. The statutes of the several states make ample provisions for the
support of the poor. It is not within the plan of this work even to give an
abstract of such extensive legislation. Vide 16 Vin. Ab. 259; Botts on the
Poor Laws; Woodf. Landl. & Ten. 901.