Mucous membrane

Thin skin lining all animal body cavities and canals that come into contact with the air (for example, eyelids, breathing and digestive passages, genital tract). It secretes mucus, a moistening, lubricating, and protective fluid.
Mucus-secreting membrane lining all body cavities or passages that communicate with the exterior; SYN. mucosa.

ETYM Latin mucosus, from mucus mucus.
Of or secreting or resembling mucus.