functional

Working properly and ready to be used.

• The old radio is still functional.
• Repairs made the heating system fully functional.
• Are all the machines functional now?

Similar words: working, operational

Opposites: broken

Common phrases: fully functional, functional equipment, remain functional

Useful for a particular job or purpose.

• This bag is attractive and functional.
• The shelves make the room more functional.
• They designed a functional kitchen with plenty of storage.

Similar words: useful, practical

Opposites: useless

Common phrases: functional furniture, functional design, functional space

Designed mainly to do a job, with little attention to decoration or beauty.

• The room has purely functional furniture.
• They built a functional concrete shelter.
• The station is functional, with little decoration.

Similar words: utilitarian, plain

Opposites: decorative

Common phrases: purely functional, functional building, functional architecture

A mathematical rule that takes a function as its input and gives a number as its result.

• This functional returns a real number.
• The integral defines a linear functional.
• We proved that the functional is continuous.

Common phrases: linear functional, continuous functional, bounded functional