Each one is a commonly used phrase to refer to individual items or people. However, there are several synonyms that can be used in its place. One such synonym is "every individual," which emphasizes the uniqueness of each item or person. Another possible replacement for "each one" is "per unit," indicating a measurement or quantity of each item. "Respective" is another suitable synonym, indicating that each person or thing has its own specific place or role. Additionally, "individual" can be used as a substitute for "each one" to emphasize the distinctiveness of each person or thing in a group or collection.