functional

adjective

func·​tion·​al ˈfəŋ(k)-sh(ə-)nəl 

1

a

: of, connected with, or being a function

the functional differences between the departments

b

: affecting physiological or psychological functions but not organic structure

functional heart disease

2

: used to contribute to the development or maintenance of a larger whole

functional and practical school courses

also : designed or developed chiefly from the point of view of use

The design of the building is not only functional but also beautiful.

3

: performing or able to perform a regular function

The flashlight was still functional after I had dropped it.

functionally

ˈfəŋ(k)-sh(ə-)nə-lē 

adverb

Synonyms of functional

• operational
• operating
• operative
• functioning

Examples of functional in a Sentence

The building's design is not only functional but also beautiful.

The flashlight was still functional after I dropped it.

The computer network is fully functional.

Recent Examples on the Web

The fashion guru has been ringing in 2026 in the ski town, stepping out in looks that blur the line between functional and fashion-forward. —Kelsey Stewart, Footwear News, 3 Jan. 2026

Green Tea Green tea is packed with plant compounds called catechins, which help reduce oxidative stress and inflammatory markers in the body, said Meena Malhotra, MD, ABOM, ABIM, a functional and integrative medicine physician and medical director at Heal n Cure. —Stephanie Anderson Witmer, Health, 2 Jan. 2026

This research shows that lignin, a primary element of wood, can be paired with a sensitizer made from plant sugars to produce functional paper for receipts and labels. —Aman Tripathi, Interesting Engineering, 2 Jan. 2026

Restaurants must not have to pay more simply to access a functional, equitable program that should already exist as a baseline. —Andrew Rigie, New York Daily News, 2 Jan. 2026

Word History

First Known Use

1633, in the meaning defined at sense 1a

Phrases Containing functional

• functional calculus
• functional food
• functional genomics
• functional group
• functional illiterate
• functional magnetic resonance imaging
• functional shift

Rhymes for functional

• junctional
• bifunctional
• dysfunctional
• nonfunctional

Kids Definition

functional

adjective

func·​tion·​al ˈfuŋ(k)-shnəl 

-shən-ᵊl

1

a

: of, connected with, or being a function

b

: affecting bodily functions but not structure

functional heart disease

2

: designed or developed chiefly from the point of view of use

functional clothes

functional writing

3

: performing or able to perform a regular function

functionally

-shnə-lē 

-shən-ᵊl-ē

adverb

Medical Definition

functional

adjective

func·​tion·​al ˈfəŋ(k)-shnəl, -shən-ᵊl 

1

a

: of, connected with, or being a function compare structural sense 1

b

: affecting physiological or psychological functions but not organic structure

functional heart disease

a functional psychosis

compare organic sense 1b

2

: performing or able to perform a regular function

functionally

-ē 

adverb