The word "有木有" is formed through homophonic substitution in informal Chinese, where the character "木" (mù) is used to phonetically mimic "没" (méi) due to their similar pronunciation, creating a playful variant of the standard phrase "有没有" (yǒu méi yǒu), which means "is there or not?" or "do you have or not?", often utilized for emphasis or humor in casual and online contexts.