Defeminization refers to the process of removing or suppressing feminine qualities or characteristics. While there are several synonyms for this term, some of the most common include masculinization, virilization, and tomboyism. Masculinization and virilization both describe the process of adopting masculine traits or characteristics, while tomboyism refers to a more playful and casual representation of traditionally masculine qualities. Other synonyms may include butchness, gender-blurring, and gender-defiance. It's worth noting that many of these terms have negative connotations, particularly when used to describe women or those who do not conform to traditional gender norms. As such, it's important to use them with care and sensitivity.