"Primarily" is a term used to denote the main or principal focus of a statement or action. However, alternate words can add variety to your writing. One option is "mainly," which provides a similar meaning to "primarily" but with a slightly different nuance. Another is "chiefly," which emphasizes a hierarchy of importance or rank. "Predominantly" is another synonym for "primarily" that emphasizes a dominance or preponderance of something. Additionally, "essentially" carries the same meaning and suggests that something is fundamental to the issue at hand. Lastly, "fundamentally" suggests that the core or foundation of something is at play.