Used in two forms, the former used more popularly;

1. Kg/m^2 of living materials in an ecosystem

2. Mob of people, population

Someone people turn to when they're sad who makes them feel better.

When all that's left of you is your body, and your soul has evacuated... i.e. to perish, to die, often by ones own hand. Often cited in the videogame 'EVE Online' due to an affect that happens to your character when it dies, resulting in a corpse floating in space with the item category: 'biomass'.

Alternative definition of a morbidly obese ham planet/land whale.