The viscous, slippery substance that consists chiefly of mucin, water, cells, and inorganic salts and is secreted as a protective lubricant coating by cells and glands of the mucous membranes.

• 粘液一种由粘膜细胞或腺分泌的作为润滑保护层的粘滑物质，主要成份为粘液、水、细胞和无机盐