lifeblood life‧blood [ˈlaɪfblʌd] noun [singular]
the most important thing needed by an organization, country etc in order to continue or develop successfully:

• Cash flow is the lifeblood of any company.

• The companies argue that patents are their lifeblood.

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lifeblood UK US /ˈlaɪfblʌd/ noun [S]
the most important thing that someone or something needs in order to continue to exist or operate: »

Education is the lifeblood of a knowledge-based economy.


She is fantastic at new product development, which is our lifeblood.

Financial and business terms. 2012.