a life preserver consisting of a connected pair of inflatable bags that fit under a person's arms and provide buoyancy; used by children learning to swim
line thrown from a vessel that people can cling to in order to save themselves from drowning
line that raises or lowers a deep-sea diver
support that enables people to survive or to continue doing something (often by providing an essential connection); "the airlift provided a lifeline for Berlin"; "she offered me a lifeline in my time of grief"