Decagon n. : A plane figure having ten sides and ten angles; any figure having ten angles. A regular decagon is one that has all its sides and angles equal.

Example:
What is the interior angle sum of a convex Decagon?

Taxonomy
Water Activity, AquaLab, Soil Moisture, Thermal Properties, Sensors, Decagon Devices, Inc, Canopy, Water Potential, KD2, Soil Moisture Sensors, Application Notes, Virtual Seminars, Decagon, isotherms, lai, stomatal conductance, soil, leaf.

Defination from the web:
Manufactures the AquaLab, a research-grade water activity meter.