(1):

(n.) The process, fact, or pressure of boycotting; a combining to withhold or prevent dealing or social intercourse with a tradesman, employer, etc.; social and business interdiction for the purpose of coercion.

(2):

(v. t.) To combine against (a landlord, tradesman, employer, or other person), to withhold social or business relations from him, and to deter others from holding such relations; to subject to a boycott.