Definition of "lifeblood" in English

noun

1. Blood that is needed for continued life; blood regarded as the seat of life.

   • You didn't come to me in time. And by the time you came to me that fool of a doctor had bled and leeched the lifeblood out of Timmy.

2. (figuratively) That which is required for continued existence or function.

   • Gasoline is the lifeblood of the modern city.