Source : Webster's Revised Unabridged Dictionary (1913)

Mastless \Mast"less\, a. [See lst {Mast}.]
   Bearing no mast; as, a mastless oak or beech. --Dryden.

Mastless \Mast"less\, a. [See 2d {Mast}.]
   Having no mast; as, a mastless vessel.