\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.