fundamental

US /ˌfʌndəˈmɛntl/

UK /ˌfʌndəˈmentl/

A2

adjective

  • Forming a necessary part, base, or core
  • Basic and essential.
  • Of central importance.

noun

  • A basic part of something
  • (Music) the lowest note in a harmony
  • A basic principle, rule, or law that serves as the groundwork of a system.