%tersanctus%

‖n. [ L. ter thrice + sanctus holy. ] (Eccl.) An ancient ascription of praise (containing the word “Holy” -- in its Latin form, “Sanctus” -- thrice repeated), used in the Mass of the Roman Catholic Church and before the prayer of consecration in the communion service of the Church of England and the Protestant Episcopal Church. Cf. Trisagion. [ 1913 Webster ]