life support

Short definition from Wiktionary

Noun

1. 1
   An artificial system designed to provide oxygen and other conditions necessary for human life in an inhospitable environment.
2. 2
   The maintenance of vital functions of a critically ill or comatose person or a person undergoing surgery.
3. 3
   The equipment and special procedures used for life support.
4. 4
   A means of sustaining existence or continuation of something, usually in an artificial manner when it should have changed or terminated in its natural environment.
5. 5
   Alternative spelling of life support.