- present participle of function.
functioning
Americanadjective
-
performing a specified action or activity; working; operating.
My son has only one functioning kidney.
-
(of a person with addiction or other illness or disability) able to cope with everyday life, as at home or at work: functioning diabetics.
a functioning alcoholic with a successful career;
functioning diabetics.
Etymology
Origin of functioning
First recorded in 1835–40; in 1970–75 functioning for def. 2; function ( def. ) (in the sense “to perform an action”) + -ing 2 ( def. )
Explanation
Something that is functioning is working — doing what it's supposed to do. A functioning refrigerator keeps your food cold. A functioning television shows a clear picture. A functioning group gets things done in an orderly and timely fashion. A function is the purpose that something is made for. A flashlight's function is to light up. But if it's not functioning, or working properly, you might need to change its batteries or buy a new one. If your car can get you from point A to point B but the engine sounds like it's going to die any minute, you might say that it is "barely functioning." Sometimes people use the word functional to mean the thing as functioning.
Vocabulary lists containing functioning
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"He found that my nerves weren't functioning properly. It wasn't very enjoyable, but I spent a couple of weeks with him, and it really, really helped."
From BBC • Jun. 30, 2026
Governor Sergey Aksyonov said individuals and businesses would be turned away from petrol stations, and fuel would only be sold to government agencies ensuring Crimea's "functioning and security".
From BBC • Jun. 21, 2026
Kids under the age of 10 with a high amount of daily screen time face significant developmental repercussions like irritability, a lack of executive functioning, poor sleep, and, critically, poor social and emotional competence.
From Salon • Jun. 21, 2026
"Our work shows amyloid beta and tau compete for the same binding sites on microtubules, and that a-beta can prevent tau from functioning correctly," Julian said.
From Science Daily • Jun. 19, 2026
Then imagine the skill required to isolate this particle, to take it apart and analyze its components and determine their highly complex functioning.
From "Silent Spring" by Rachel Carson
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
