Pronunciation: (līf'līn"), [key]
1. a line, fired across a ship or boat, by means of which a hawser for a breeches buoy may be hauled aboard.
2. a line or rope for saving life, as one attached to a lifeboat.
3. any of various lines running above the decks, spars, etc., of a ship or boat to give sailors something to grasp when there is danger of falling or being washed away.
4. a wire safety rope supported by stanchions along the edge of the deck of a yacht.
5. the line by which a diver is lowered and raised.
6. any of several anchored lines used by swimmers for support.
7. a route or means of transportation or communication for receiving or delivering food, medicine, or assistance: This road is the town's lifeline and must be kept open despite the snow.
8. assistance at a critical time.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.