mucus Meaning, Definition & Usage

  1. noun protective secretion of the mucus membranes; in the gut it lubricates the passage of food and protects the epithelial cells; in the nose and throat and lungs it can make it difficult for bacteria to penetrate the body through the epithelium
    mucous secretion.

WordNet

Mu"cus noun
Etymology
L. mucus, muccus; cf. mucere 8be moldy or musty, Gr. mucus, and Skr. muc to release. Cf. Match for striking fire, Moist, Mucilage.
Definitions
  1. (Physiol.) A viscid fluid secreted by mucous membranes, which it serves to moisten and protect. It covers the lining membranes of all the cavities which open externally, such as those of the mouth, nose, lungs, intestinal canal, urinary passages, etc.
  2. (Physiol.) Any other animal fluid of a viscid quality, as the synovial fluid, which lubricates the cavities of the joints; -- improperly so used.
  3. (Bot.) A gelatinous or slimy substance found in certain algæ and other plants.

Webster 1913