(1):

(n.) A spring of water; hence, water, or a pure, transparent liquid like water.

(2):

(n.) A fluid containing certain products resulting from the growth of specific microorganisms upon some culture medium, and supposed to be possessed of curative properties.

(3):

(n.) An alkaline colorless fluid, contained in the lymphatic vessels, coagulable like blood, but free from red blood corpuscles. It is absorbed from the various tissues and organs of the body, and is finally discharged by the thoracic and right lymphatic ducts into the great veins near the heart.

(4):

(n.) A fibrinous material exuded from the blood vessels in inflammation. In the process of healing it is either absorbed, or is converted into connective tissue binding the inflamed surfaces together.