heartbeat
noun
1 [C, U] the movement or sound of the heart as it pumps blood around the body:
a rapid / regular heartbeat
2 [sing.] the ~ of sth (AmE) an important feature of sth, that is responsible for making it what it is:
The candidate said that he understood the heartbeat of the Hispanic community in California.

• Từ đồng nghĩa / Synonyms: pulse   pulsation   beat