The term 'Lifeline' can be defined in three ways. The first is 'SALVATION', which is a nine-letter word meaning the act of saving or preserving from harm, destruction, or loss. The second is 'BIOGRAPHER', which is a ten-letter word meaning a person who writes the biography of another person. The third is 'RESCUE', which is a six-letter word meaning to free from danger or confinement. All three words are related to the concept of lifeline, as they all refer to the act of saving someone or something from a difficult situation.