1. Fit or ready for use or service; SYN. usable, useable, in working order, operable, operational.
2. Relating to or based on function especially as opposed to structure or esthetics.
3. Designed for or capable of a particular function or use.
4. Designed for or adapted to a function or use.
5. (Pathology) Involving or affecting function rather than physiology.

Singular of functional languages is functional language.

Množina: functional partitionings

Množina: functional tests

Množina: functional units

Množina: functionalisms

1. A psychology based on the assumption that all mental process are useful to an organism in adapting to the environment.
2. Any doctrine that stresses utility or purpose.
doctrine emphasising utility and function
In architecture and design, the principle of excluding everything that serves no practical purpose. Central to 20th-century Modernism, the Functionalist ethic developed as a reaction against the 19th-century practice of imitating and combining earlier styles. Its finest achievements are in the realms of industrial architecture and office furnishings.
Leading exponents of Functionalism were the German Bauhaus school, the Dutch group De Stijl, and the Scandinavians, especially the Swedish and Finnish designers. Prominent architects in the field were Le Corbusier and Walter Gropius.
In the social sciences, the view of society as a system made up of a number of interrelated parts, all interacting on the basis of a common value system or consensus about basic values and common goals. Every social custom and institution is seen as having a function in ensuring that society works efficiently; deviance and crime are seen as forms of social sickness.
Functionalists often describe society as an organism with a life of its own, above and beyond the sum of its members. The French sociologists Auguste Comte and Emile Durkheim and the American Talcott Parsons assumed functionalist approaches for their studies.

Množina: functionalities

1. A feature of an apparatus or of a computer program.
2. The way in which something functions.