Brown-nose is a term used to describe someone who shows excessive flattery or seeks to please others in order to gain favor or advancement. The opposite of this behavior would be someone who is independent, self-sufficient, and not concerned with pleasing others for personal gain. A person who does not engage in brown-nosing is authentic, genuine, and true to themselves. They focus on their own strengths and capabilities rather than relying on others for advancement. They do not engage in false flattery or compromise their integrity for personal gain. Therefore, antonyms for brown-nose could be independent, self-sufficient, genuine, or authentic.