Borrowed Time Meaning

(idiomatic) A period of time whose precise duration is not known but which can be expected to be quite limited, and at the end of which one's situation, benefits, or opportunities will be entirely terminated.

Example: 1920, Lucy Maud Montgomery, Rilla of Ingleside, ch. 31:
  [A]t eighty a body is living on borrowed time.
1957 Aug. 12, Herman N. Bundesen MD, "Diet and Health, Lewiston Daily Sun (USA), p. 3 (retrieved 28 June 2011):
  A century ago you could expect to live 40 years. . . . Anything beyond that was borrowed time.
1997 Aug. 25, Christopher Clarey, "Ho Returns In Time To Say Farewell," New York Times (retrieved 28 June 2011):
  "Basically, my back is a career-ending injury." . . . It might seem like a Faustian bargain, but Ho is making the best of his borrowed time.
2011, Lisa Wingate, Larkspur Cove, ISBN 9780764208218, p. 193:
  The thing about borrowed time is that it always runs out quicker than you want it to.