Source : Webster's Revised Unabridged Dictionary (1913)

Consubstantial \Con`sub*stan"tial\, a. [L. consubstantialis;
   con- + substantialis: cf. F. consubstantiel. See
   {Substantial}.]
   Of the same kind or nature; having the same substance or
   essence; coessential.

         Christ Jesus . . . coeternal and consubstantial with
         the Father and with the Holy Ghost.      --Foxe.

Source : WordNet®

consubstantial
     adj : regarded as the same in substance or essence (as of the
           three persons of the Trinity)