The Collaborative International Dictionary of English v.0.48:

Ham \Ham\ (h[aum]m), n.
   Home. [North of Eng.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ham \Ham\ (h[a^]m), n. [AS. ham; akin to D. ham, dial. G. hamme,
   OHG. hamma. Perh. named from the bend at the ham, and akin to
   E. chamber. Cf. Gammon ham.]
   [1913 Webster]
   1. (Anat.) The region back of the knee joint; the popliteal
      space; the hock.
      [1913 Webster]

   2. The thigh of any animal; especially, the thigh of a hog
      cured by salting and smoking.
      [1913 Webster]

            A plentiful lack of wit, together with most weak
            hams.                                 --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ham \Ham\ (h[a^]m), n.
   1. [Short for hamfatter.] a person who performs in a showy
      or exaggerated style; -- used especially of actors. Also
      used attributively, as, a ham actor.
      [PJC]

   2. The licensed operator of an amateur radio station.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Ham \Ham\ (h[a^]m), v. i. (Theater)
   To act with exaggerated voice and gestures; to overact.
   [PJC]

   ham it up to act in a showy fashion or to act so as to
      attract attention; to ham. [Colloq.]
      [PJC]

WordNet (r) 3.0 (2006):

ham
    n 1: meat cut from the thigh of a hog (usually smoked) [syn:
         ham, jambon, gammon]
    2: (Old Testament) son of Noah
    3: a licensed amateur radio operator
    4: an unskilled actor who overacts [syn: ham, ham actor]
    v 1: exaggerate one's acting [syn: overact, ham it up,
         ham, overplay] [ant: underact, underplay]

The Jargon File (version 4.4.7, 29 Dec 2003):

ham


    The opposite of spam, sense 3; that is, incoming mail that the user
    actually wants to see.