Not one is a phrase that typically means none or zero, and is often used when referring to a group or collection. Some common synonyms for not one include none, zero, nil, no one, nobody, and nothing. These words can be used interchangeably in sentences to convey the same meaning. For example, "Not one of the students showed up to class today," could also be written as "None of the students showed up to class today." Other synonyms for not one could include words like empty, vacant, void, or barren. These words can be used to describe a space or area that is completely without something and can also be used to express the idea of not having anything at all.