- the total number of living organisms in a given area, expressed in terms of living or dry weight per unit area
WordReference Random House Unabridged Dictionary of American English © 2019
- Ecologythe amount of living matter in a given habitat, expressed either as the weight of organisms per unit area or as the volume of organisms per unit volume of habitat.
- Energyorganic matter, esp. plant matter, that can be converted to fuel and is therefore regarded as a potential energy source.
- bio- + mass 1930–35