DEFERENT is a 8 letter word that starts with D.

1. \Def"er*ent\, a. [L. deferens, p. pr. of deferre. See
   3d {Defer}.]
   Serving to carry; bearing. [R.] ``Bodies deferent.'' --Bacon.
   
   

2. \Def"er*ent\, n.
   1. That which carries or conveys.
   
            Though air be the most favorable deferent of sounds.
                                                  --Bacon.
   
   2. (Ptolemaic Astron.) An imaginary circle surrounding the
      earth, in whose periphery either the heavenly body or the
      center of the heavenly body's epicycle was supposed to be
      carried round.