Synonyms: nonfunctional, malfunctioning
Definition: not performing or able to perform its regular function
Usage: a malfunctioning valve
Similar words: wrong, amiss, awry, haywire
Definition: not functioning properly
Usage: something is amiss; has gone completely haywire; something is wrong with the engine
Definition: not working properly
Usage: a bad telephone connection; a defective appliance
Similar words: out of whack
Definition: out of balance or out of adjustment
Usage: the front wheel of my bicycle is out of whack
Similar words: run-down
Definition: having the spring unwound
Usage: a run-down watch