The Collaborative International Dictionary of English v.0.48:

Concenter \Con*cen"ter\, Concentre \Con*cen"tre\, v. i. [imp. &
   p. p. Concentered or Concentred; p. pr & vb. n.
   Concenteringor Concentring.] [F. concentrer, fr. L. con-
   + centrum center. See Center, and cf. Concentrate]
   To come to one point; to meet in, or converge toward, a
   common center; to have a common center.
   [1913 Webster]

         God, in whom all perfections concenter.  --Bp.
                                                  Beveridge.
   [1913 Webster] Concenter