beating heart

beating heart (plural beating hearts)

1. (figuratively) The core of a thing; its most essential or important part.

   Synonym: heart and soul

   the beating heart of the economy

   • 2024 April 3, Phil McNulty, “Man City 4-1 Aston Villa: Phil Foden produces 'masterclass' to show worth again”, in BBC‎:

     This was an outstanding Manchester City performance, the old quality back on show, but Foden was its beating heart, the peerless Rodri also playing his part.

2. Used other than figuratively or idiomatically: see beating,‎ heart.

   beating-heart transplant

   be still my beating heart

• heartbeat

• “the beating heart of something”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.