The Collaborative International Dictionary of English v.0.48:

Almoner \Al"mon*er\ ([a^]l"m[u^]n*[~e]r), n. [OE. aumener,
   aulmener, OF. almosnier, aumosnier, F. aum[^o]nier, fr. OF.
   almosne, alms, L. eleemosyna. See Alms.]
   1. One who distributes alms, esp. the doles and alms of
      religious houses, almshouses, etc.; also, one who
      dispenses alms for another, as the almoner of a prince,
      bishop, etc.
      [1913 Webster]

   2. A social worker in a hospital. [Chiefly Brit.]
      [PJC]

   3. An official in a hospital whose job it is to calculate how
      much a patient must pay for treatment. [Chiefly Brit.]
      [PJC]

WordNet (r) 3.0 (2006):

almoner
    n 1: an official in a British hospital who looks after the
         social and material needs of the patients [syn: almoner,
         medical social worker]