fundamental

/ˌfən-də-ˈmen-tᵊl/

Middle English, borrowed from Late Latin fundāmentālis "serving as a foundation," from Latin fundāmentum "foundation, basis" + -ālis

adjective

  1. serving as a basis supporting existence or determining essential structure or function : basic

  2. serving as an original or generating source : primary

  3. of or relating to essential structure, function, or facts : radical; also : of or dealing with general principles rather than practical application

Responsibility is fundamental to democracy.

a discovery fundamental to modern computers

essential fundamental vital cardinal mean so important as to be indispensable. essential implies belonging to the very nature of a thing and therefore being incapable of removal without destroying the thing itself or its character. fundamental applies to something that is a foundation without which an entire system or complex whole would collapse.

noun

  1. something fundamental; especially : one of the minimum constituents without which a thing or a system would not be what it is

  2. the principal musical tone produced by vibration (as of a string or column of air) on which a series of higher harmonics is based

  3. the root of a chord

noun

  1. a set that is a subset of all paths defined on a set of points each pair of which is joined by a path and that is the quotient group of the group of all paths beginning and ending in a given point