When looking for synonyms for "not either one," several options come to mind. Some examples include "neither," "none," "nothing," or "nobody." These words denote a lack of presence or absence of choice between two or more options. Another synonym that can be used in certain contexts is "nonbinary," which refers to a person who does not identify as male or female. It's vital to choose the right word for the situation to convey the intended meaning. Overall, having a diverse vocabulary is crucial in effective communication, as it allows for clear and concise expression of thoughts and ideas.