The word "N-ON" may not be a word you hear or see very often, but there are still synonyms that can be used in its place. Some similar words might be turned off, inactive, non-functioning, or idle. Depending on the context in which the word is used, other synonyms could include out of order, unresponsive, non-operational, or disconnected. These synonyms all refer to a lack of operation or function in some way, and may be used interchangeably with "N-ON" to convey the same meaning. No matter which synonym is used, the message remains clear that something is not functioning as it should be.