Excommunicate \Ex`com*mu"ni*cate\, v. t. [imp. & p. p. {Excommunicated}; p. pr. & vb. n. {Excommunicating}.] 1. To put out of communion; especially, to cut off, or shut out, from communion with the church, by an ecclesiastical sentence. [1913 Webster] 2. To lay under the ban of the church; to interdict. [1913 Webster] Martin the Fifth . . . was the first that excommunicated the reading of heretical books. --Miltin. [1913 Webster]