Aumbry. A small cupboard, generally on the north side of the sanctuary. Its use is a little confusing; when Anglican churches returned, with some enthusiasm, to the practice of reserving the blessed sacrament in the late 19th century, aumbries were used, and in some cases built, to contain it. A light burned outside the door of the aumbry to denote the presence of the sacrament. Today in Suffolk, it is quite rare to see the sacrament reserved, but this arrangement can be seen at, amongst other places, Thornham Parva, Ufford and Ipswich St Mary le Tower.
However, there is some evidence to show that the aumbry had a different purpose in medieval times, and that the sacrament would have been reserved in a pyx. Instead, the aumbry contained those objects considered sacred rather than just valuable: the chrismatory with its holy oils, the altar vessels, etc.
Catholic churches generally reserve the sacrament in a tabernacle.