Malfunction
Part of speech: noun
Definition: Faulty functioning. Failure to function.
Part of speech: verb
Definition: To function improperly To fail to function
Example sentence: I was living in a small town in Indiana working as a telemarketer and a vacuum salesman. I was really bad: the vacuums seemed to always be falling apart. Every time I did a demonstration, I'd say, 'This is the material the astronauts used on Apollo 13.' And no sooner had that come out of my mouth, something would malfunction.
Misfunction
Part of speech: verb
Definition: To function incorrectly; to malfunction