Lifeline/ˈlaɪflaɪn/ Definition 1 of 4Pro Tip 1/2Metaphoric Connection Understand 'lifeline' beyond physical means; see it as essential support like water for life. Internet access is a lifeline for remote workers. Pro Tip 2/2Not Always Literal 'Lifeline' can be people, organizations, or services, not just objects. 24-hour support services act as a lifeline for those in crisis.