When you catch a cold, mucus comes out of your nose.
Snails move by secreting a viscous liquid.
粘膜 is the moist tissue lining body cavities, while 粘液 is the slippery fluid that the 粘膜 secretes.
mucous stool; mucous feces
myxoma; mucous tumor
mucous gland
phlegmatic temperament
mucic acid
Compound of 粘 (nen, 'sticky') and 液 (eki, 'liquid'). The kanji straightforwardly represent the meaning.