Quadrat n. : A block of type metal lower than the letters, -- used in spacing and in blank lines.

Quadrat n. : An old instrument used for taking altitudes; -- called also geometrical square, and line of shadows.

Example:
How can I estimate the population of grass plants using the Quadrat method?

Taxonomy
Quadrat, square, free encyclopedia, percentage, ecology, types of vegetation, vegetation present, search, measure, species, random place, vegetation, Personal tools, Interaction, Toolbox, non-profit organization, disambiguation, rectangle.

Defination from the web:
quadrat is a measured and marked rectangle, often a square, used in ecology to isolate a sample. It usually consists of 100 squares. In ecology, you usually place the quadrat down in a specific or random place and count what vegetation occurs in each square. ...