The word "un-masculine" implies a lack of traits or qualities that are stereotypically associated with masculinity, such as strength, bravery, and dominance. Antonyms for this word would be "masculine," meaning having these traits, or "manly," meaning possessing qualities that are typically associated with men or male behavior, such as courage, toughness, and decisiveness. Other antonyms include "assertive," "bold," "confident," and "assertive," all of which convey a sense of strength or dominance. These words can be used to describe both men and women who possess these qualities, breaking down gender stereotypes and promoting equality.