The phrase "one of two" is often used to refer to a situation where there are only two options available for a decision or choice. However, there are many synonyms that can be used to express this meaning. Some of these include "either of two," "one or the other," "one of a pair," "one or the second," "the first of two," "the earlier of two," and "the initial of two." These synonyms can be used in a range of contexts, such as in conversations, debates, or in written works. By using synonyms for "one of two," one can communicate ideas effectively and succinctly, while avoiding repetition.