malfunctioning
adjectiveUK /ˌmælˈfʌŋkʃənɪŋ/
US /ˌmælˈfʌŋkʃənɪŋ/
Not working the way it should.
The malfunctioning robot kept spinning in circles.
OTHER MEANINGS
2. The act of a machine or system failing to work properly.
Engineers studied the malfunctioning of the old elevator.
3. Behaving in an abnormal or faulty way.
The malfunctioning alarm went off at random times.
4. A failure in a body part or organ to work correctly.
Doctors treated a malfunctioning valve in his heart.