In mathematics, especially linear algebra and functional analysis, a function that maps a vector, function, or other mathematical object to a single scalar value.

The linear functional f(v) = v₁ + v₂ assigns a scalar to every vector in ℝ².

functionaladjektiv

Designed to be practical and useful, rather than attractive.

The new office furniture is functional, providing ample storage and workspace.

In working order; operating correctly.

The old radio is still functional despite its age.

Relating to the way in which something works or operates.

The functional aspects of the software were thoroughly tested before release.

Of a disease or disorder: affecting physiological function without detectable structural change.

The neurologist suspected a functional disorder rather than an organic lesion.