lifeline

• POS: Noun
• HYPHEN: life=line

CIDE DICTIONARY

lifeline, n. 

•  The anem given to one of the creases on the palm; its length is said by palmists to indicate how long one will live.  [WordNet 1.5]
•  A line or rope which raises or lowers a deep-sea diver.  [WordNet 1.5]
•  A line from a vessel that people in a body of water can cling to to save themselves from drowning.  [WordNet 1.5]

OXFORD DICTIONARY

lifeline, n.
1 a a rope etc. used for life-saving, e.g. that attached to a lifebuoy. b a diver's signalling line.
2 a sole means of communication or transport.
3 a fold in the palm of the hand, regarded as significant in palmistry.
4 an emergency telephone counselling service.

THESAURUS

lifeline

Mae West, aegis, arm guard, backstop, bolt-hole, breeches buoy, buffer, bulwark, bumper, buoy, contraceptive, copyright, cork jacket, crash helmet, cushion, dashboard, dodger, ejection capsule, ejection seat, ejector seat, emergency exit, escape hatch, face mask, fender, finger guard, fire escape, foot guard, fuse, goggles, governor, guard, guardrail, hand guard, handrail, hard hat, helmet, inflatable slide, insulation, interlock, knee guard, knuckle guard, laminated glass, life belt, life buoy, life jacket, life net, life preserver, life raft, life ring, life vest, lifeboat, lightning conductor, lightning rod, mask, mudguard, nose guard, pad, padding, palladium, parachute, patent, pilot, preventive, prophylactic, protective clothing, protective umbrella, rubber dinghy, safeguard, safety, safety belt, safety glass, safety plug, safety rail, safety shoes, safety switch, safety valve, sally port, screen, seat belt, shield, shin guard, slide, sun helmet, umbrella, water wings, windscreen, windshield