The Collaborative International Dictionary of English v.0.48:

Codger \Codg"er\, n. [Cf. Cadger.]
   1. A miser or mean person.
      [1913 Webster]

   2. A singular or odd person, especially an old man; -- a
      familiar, humorous, or depreciatory appellation. [Colloq.]
      [1913 Webster]

            A few of us old codgers met at the fireside.
                                                  --Emerson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

codger
    n 1: used affectionately to refer to an eccentric but amusing
         old man [syn: codger, old codger]