The term "simp" is a slang word often used in internet culture to describe someone, usually a male, who shows excessive sympathy and attention toward someone they are attracted to, often to the point of compromising their own dignity or self-respect. It implies that the individual is overly eager to please or support the object of their affection, without receiving similar respect or affection in return.
The word "simp" is believed to be a shortened form of "simpleton," which historically refers to a person who is considered foolish or lacking in intelligence. In modern usage, it has evolved to refer specifically to someone who is perceived as too nice or submissive, particularly in romantic contexts.