Definition: Astringent

Astringents are medicines which condense and coagulate the tissues,
thereby arresting discharges. When taken into the mouth, they produce the sensation known as puckering. They are used internally and locally. The term styptic is used as a synonym of astringent, but is generally employed to designate those astringents which arrest haemorrhage, or bleeding.

Source: The People's Common Sense Medical Adviser in Plain English or, Medicine Simplified, R.V. Pierce.