1. [adj]  numbered or proceeding by tens; based on ten; "the decimal system"
2. [adj]  containing ten or ten parts

DENARY is a 6 letter word that starts with D.

1. \Den"a*ry\, a. [L. denarius. See 2d {Denier}.]
   Containing ten; tenfold; proceeding by tens; as, the denary,
   or decimal, scale.
   
   

2. \Den"a*ry\, n.
   1. The number ten; a division into ten.
   
   2. A coin; the Anglicized form of denarius. --Udall.