Inofficious is an unusual word because it is not commonly used in everyday language. Synonyms for inofficious include unhelpful, ineffective, irrelevant, and useless. These words all refer to something that does not serve a purpose or provide any benefit, and they can be used interchangeably with inofficious. Other words that could be considered synonyms for inofficious include pointless, fruitless, and wasteful. Despite their slight variations in meaning, these words all convey the same basic idea: something that is inofficious is not worth having or doing because it is not useful or effective.