The word "un handy" can be replaced with several synonyms depending on the context. For instance, if you mean "not useful," "ineffective" could be used. If you're trying to describe something "difficult to manipulate," "awkward" or "cumbersome" could be more appropriate. Similarly, if you mean "not practical," words like "impractical," "unfeasible," or "unworkable" could convey the same meaning. Additionally, you could use phrases such as "not user-friendly" or "inconvenient" to describe something that's not easy to use. Overall, there are many synonyms for "un handy," each with their unique nuances and levels of formality.