I. noun 1. the regions of the surface and atmosphere of the earth or another planet occupied by living organisms. 2. an artificial structure enclosing a self-contained ecosystem or ecosystems. • the elliptical domed biosphere is the largest single-span glasshouse in the world.
II. derivatives biospheric adjective
– origin late 19th cent.: coined in German from Greek bios ‘life’ + sphaira (see sphere).