The Collaborative International Dictionary of English v.0.48:

Congruent \Con"gru*ent\, a. [L. congruens, p. pr. of congruere:
   cf. F. congruent.]
   Possessing congruity; suitable; agreeing; corresponding.
   [1913 Webster]

         The congruent and harmonious fitting of parts in a
         sentence.                                --B. Jonson.
   [1913 Webster]

   Congruent figures (Geom.), concurring figures.
      [1913 Webster]