life support is a noun meaning "equipment that makes life possible in otherwise deadly environmental conditions". It carries 2 recorded senses.
equipment that makes life possible in otherwise deadly environmental conditions
“the astronauts relied on their life-support systems”
medical equipment that assists or replaces important bodily functions and so enables a patient to live who otherwise might not survive
“the patient is on life support”
Definitions, synonyms and semantic relations for life support come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.