Source : Webster's Revised Unabridged Dictionary (1913)

Commensurable \Com*men"su*ra*ble\, a. [L. commensurabilis; pref.
   com- + mensurable. See {Commensurate}, and cf.
   {Commeasurable}.]
   Having a common measure; capable of being exactly measured by
   the same number, quantity, or measure. --
   {Com*men"su*ra*ble*ness}, n.

   {Commensurable numbers} or {quantities} (Math.), those that
      can be exactly expressed by some common unit; thus a foot
      and yard are commensurable, since both can be expressed in
      terms of an inch, one being 12 inches, the other 36
      inches.

   {Numbers}, or {Quantities}, {commensurable in power}, those
      whose squares are commensurable.