The Collaborative International Dictionary of English v.0.48:

Copts \Copts\ (k[o^]pts"), n. pl.; sing. Copt (k[o^]pt). [See
   Coptic.] (Etnol.)
   1. An Egyptian race thought to be descendants of the ancient
      Egyptians.
      [1913 Webster]

   2. The principal sect of Christians in Egypt and the valley
      of the Nile.
      [1913 Webster]

   Note: they belong to the Jacobite sect of Monophysite
         Christians, and for eleven centuries have had
         possession of the patriarchal chair of Alexandria.
         [1913 Webster]

WordNet (r) 3.0 (2006):

Copt
    n 1: an Egyptian descended from the ancient Egyptians
    2: a member of the Coptic Church