A "yes man" is someone who constantly agrees with everything someone else says or does, regardless of their own opinions or beliefs. This can sometimes be seen as a negative trait, as it shows a lack of independent thinking or assertiveness. Synonyms for "yes man" include sycophant, toady, lackey, henchman, and flatterer. These terms all describe someone who is willing to do whatever it takes to please those in power, often at the expense of their own integrity or honesty. While some may see these traits as valuable in certain situations, others may view them as potentially harmful or manipulative.