n a crease on the palm; its length is said by palmists to indicate how long you will live
n 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
n line that raises or lowers a deep-sea diver
n line thrown from a vessel that people can cling to in order to save themselves from drowning