quadrable

from The Century Dictionary.

• In geometry, capable of being squared; having an area exactly equal to that of an assignable square; also, capable of being integrated in finite terms; capable of having its definite integral expressed in exact numerical terms.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Math.) That may be sqyared, or reduced to an equivalent square; -- said of a surface when the area limited by a curve can be exactly found, and expressed in a finite number of algebraic terms.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective mathematics Of a plane figure, for which quadrature is possible.