originally a thick slice of bread, used as a primitive form of plate for eating and for slicing meat (hence its derivation from trancherto cut, or carve), but by the 14th century a square or circular wooden plate of rough workmanship. There was usually a small cavity for salt in the rim of the wooden plate, and sometimes the main section was so formed that it could be turned over and the other side used for a second course. By the beginning of the 17th century trenchers were being replaced, first by pewter ware, then by earthenware and porcelain, though the word was still used occasionally to refer to cheap plates not made of wood. It still survives in phrases such as trencherman, describing a hearty eater.
TRENCHER
Meaning of TRENCHER in English
Britannica English vocabulary. Английский словарь Британика. 2012