When looking for synonyms for the word "unresponding," there are several options available depending on the specific context in which the word is being used. For example, "unresponsive," "unreactive," and "uncommunicative" are all good synonyms if referring to someone who is not answering or engaging in conversation. If referring to a computer or machine that isn't functioning properly, "unyielding" or "uncooperative" may be more appropriate. "Inactive," "idle," and "dormant" could also be used to describe something that is not responding or reacting. Regardless of the specific synonym used, each can help to communicate the idea of something unwilling or unable to respond in some way.