- Phlegm - Slimy secretion - 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. - Any other animal fluid of a viscid quality, as the synovial
fluid, which lubricates the cavities of the joints; -- improperly so
used. - A gelatinous or slimy substance found in certain algae and
other plants.