[ek-oh-sfeer, ee-koh-] 
| 1. | Also called physiological atmosphere. the part of the atmosphere in which it is possible to breathe normally without aid: the portion of the troposphere from sea level to an altitude of about 13,000 ft. (4000 m). |
| 2. | Ecology. the planetary ecosystem, including all the earth's living organisms and their physical environment; biosphere. |
| e·co·sphere (ē'kō-sfîr', ěk'ō-) n. The regions of the universe, especially on the earth, that are capable of supporting life; the biosphere. |
| ecosphere (ē'kō-sfîr') Pronunciation Key
The regions of the Earth that are capable of supporting life, together with the ecosystems they contain; the biosphere. |
oʊˌsfɪər