diuretic:

an agent that increases the amount of urine excreted. 

A drug that lowers blood pressure by stimulating fluid loss; promotes urine production. 

a medication that lowers blood pressure by causing excess fluid to be excreted. 

a medication that helps the kidneys to remove excess fluids from the body, lowering blood pressure as well as decreasing edema (swelling). 

A drug that causes the body to excrete sodium (salt). These drugs work by making the kidneys produce more urine, hence more salt is lost.