: to function imperfectly or badly : fail to operate normally.

Where did the word malfunction come from?

malfunction (n.)

"a faulty functioning, a failure to function as expected," 1827, from mal- "bad, badly, wrong" + function. As a verb, "to fail to function normally or as expected," by 1888.

What is an example of a malfunction?

The definition of a malfunction is something that does not work properly. An example of a malfunction is a broken piece of equipment in a stereo system.