Is it ensure, insure, or assure?
1570s, from French armoire, from Old French armarie (12c.) "cupboard, bookcase, reliquary," from Latin armarium "closet, chest, place for implements or tools," from arma "gear, tools, arms" (see arm (n.2)). Before being reborrowed from French, the word earlier was in English as ambry (late 14c.).
large two-door cupboard, usually movable and containing shelves, hanging space, and sometimes drawers. It was originally used for storing arms. The armoires designed by Andre-Charles Boulle, the cabinetmaker to Louis XIV in the late 17th century, are among the most sumptuous and imposing pieces of Western furniture.