The term 'kind of drop' can refer to several different types of drops. A TEAR is a drop of liquid that comes from the eyes, usually due to emotion. A COUGH is a sudden expulsion of air from the lungs, often accompanied by a sound and the release of phlegm or mucus. MAIL is a type of drop that is sent through the postal service. LEMON is a type of drop that is acidic in nature and is often used in cooking or as a flavoring. DEW is a type of drop that forms on cool surfaces when the air is saturated with moisture. Finally, GUM is a type of drop that is chewed for its flavor and texture.