Incubator (?), n.
1. That which incubates, especially, an apparatus by means of which eggs are hatched by artificial heat.
[1913 Webster]
2. An apparatus containing an enclosed chamber, used for the cultivation of microörganisms or tissue cultures by maintaining a suitable temperature and atmospheric composition. Some incubators have no provision for maintaining a special atmosphere, while in others, especially for anaerobic organisms and tissue culture, the moisture level and composition of the gases are also controlled.
[Webster 1913 Suppl. +PJC]
3. (Med.) An apparatus consisting of enclosed chamber, for maintaining prematurely born babies in a favorable environment until able to thrive under normal conditions. The temperature and level of oxygen in the atmosphere may be controlled.
[Webster 1913 Suppl. +PJC]