三八 is a colloquial, often derogatory term — originally associated with International Women's Day (March 8) — used to describe someone, typically a woman, who is silly, naive, overly emotional, gossipy, or acting in an exaggeratedly feminine way. It can be used as an insult or, among close friends, as playful teasing. Be cautious with its use; it is considered offensive in formal or polite contexts.