Definitions for quadratˈkwɒd rət
Random House Webster's College Dictionary
Ref: quad2 (def. 1). 1 2 1
a square or rectangular plot of land marked off for the study of plants and animals.
Origin of quadrat:
1675–85; var. of quadrate
a block of type metal lower than the letters, -- used in spacing and in blank lines
an old instrument used for taking altitudes; -- called also geometrical square, and line of shadows