The Collaborative International Dictionary of English v.0.48:

Comportment \Com*port"ment\, n. [F. comportement.]
   Manner of acting; behavior; bearing.
   [1913 Webster]

         A graceful comportment of their bodies.  --Cowley.
   [1913 Webster]

         Her serious and devout comportment.      --Addison.
   [1913 Webster]

WordNet (r) 3.0 (2006):

comportment
    n 1: dignified manner or conduct [syn: bearing, comportment,
         presence, mien]