Mucus

Mucus

Noun · /ˈmjuː.kəs/

Definition

A slimy substance secreted by mucous membranes and glands; the thick, slippery fluid produced by the lining of the nose, throat, lungs, and digestive system that lubricates and protects the epithelial surfaces.

Origin

From Latin mucus (nasal mucus, slime), related to mucere (to be mouldy, to be slimy), from Proto-Indo-European *meuk- (to slip, be slimy). The adjective form mucous (relating to mucus) and mucous membrane being the standard clinical terms. The common confusion between mucus (noun: the substance) and mucous (adjective: relating to mucus, or secreting mucus) being a frequent spelling error. The biological role of mucus being far more complex and important than the colloquial association with illness and disgust suggests.