阳刚 describes the traditional masculine qualities of strength, courage, and assertiveness — a positive trait in Chinese culture often contrasted with 阴柔 (feminine softness). It's used to characterize a man's demeanor, appearance, or spirit (e.g., 阳刚之气 'masculine aura'). The English equivalents 'manly' or 'virile' capture the core meaning but miss the cultural weight and the yin-yang opposition that frames the term.