Nether

прилагательное [литературно-книжное] нижний, более низкий Например: nether jaw — нижняя челюсть Например: hard as a nether millstone — твёрд как кремень

Большой англо-русский словарь

Nether

adjective Etymology: Middle English, from Old English nithera, from nither down; akin to Old High German nidar down, Sanskrit ni 1. situated down or below; lower Example: the nether side 2. situated or believed to be situated beneath the earth's surface Example: the nether regions

Merriam-Webster's Collegiate Dictionary