The word "绑匪" is formed by combining the character "绑", which means to bind or tie, derived from the silk radical (纟) indicating connection and the phonetic component "邦" suggesting pronunciation, with the character "匪", meaning bandit or robber, originally conveying illegality. Together, they create a compound where "绑" denotes the action of restraining and "匪" specifies the perpetrator, resulting in a term that directly refers to a kidnapper who binds victims.