Nether-region Definition

(often pluralized) Hell; a realm beneath the surface of the earth conceived as the abode of the souls of the dead and, sometimes, as the abode of demons or evil spirits.

(often pluralized, by extension) A place which is subterranean or enclosed beneath a surface, especially one which is dark, dank, or otherwise inhospitable.

(often pluralized, euphemistic, sometimes humorous) The groin or buttocks.