Meaning : A crease on the palm. Its length is said by palmists to indicate how long you will live.
Synonyms : life line, line of life
Meaning : Support that enables people to survive or to continue doing something (often by providing an essential connection).
Example :
The airlift provided a lifeline for Berlin.
She offered me a lifeline in my time of grief.
Meaning : Line that raises or lowers a deep-sea diver.
Meaning : Line thrown from a vessel that people can cling to in order to save themselves from drowning.
Lifeline meaning in Bengali (Bangla).