Mucus (noun)

1. A thick, slippery substance that is produced by the lining of certain parts of the body, such as the nose or the lungs, and that helps to protect and moisturize these areas.
2. A viscous, slimy mixture of water, electrolytes, mucin, white blood cells, and other substances that is secreted by glands lining the nasal, oral, and other body cavities.

Origin:

From latin word "mucus".

Examples:

1. The mucus was thick and hard to blow out of his nose.
2. The mucus in her throat made it hard for her to speak.
3. The mucus was clear and thin, indicating that she was not sick.
4. The mucus in her lungs made it hard for her to breathe.
5. The mucus helped to trap foreign particles and protect her respiratory system.