fundamental
adjectiveUK /ˌfʌn.dəˈmen.təl/
US /ˌfʌn.dəˈmen.t̬əl/
Something fundamental is the most basic and important part of a thing.
Reading is a fundamental skill that every child needs to learn.
RELATED WORDS
OTHER MEANINGS
2. Forming the base or foundation that something is built on.
The fundamental rules of the game are easy to understand.
3. A basic rule or principle that explains how something works.
Honesty is a fundamental of a good friendship.
4. Very great or important in a way that changes everything.
The new law made a fundamental change to how schools work.