The phrase "one time" refers to an event that occurred only once. However, there are several other synonyms that can be used to express the same idea. For instance, "once" is a commonly used synonym for "one time." Other alternatives include "singularly," "solely," "a solitary occasion," "a singular occurrence," and "a lone instance." These synonyms can be used interchangeably depending on the context. For example, instead of saying "I only met her one time," one could say "I met her once," or "I met her a solitary occasion." Using these synonyms can help to add variety to one's vocabulary and make their writing or speech more interesting.