The drop is a unit of measure of volume. It is a variable amount of fluid and depends on the device and technique used to produce the drop and on the physical properties of the fluid. This is similar to units like the cup, tablespoon, and teaspoon that depend on the spoon or cup and are not exact either. See:- Physical unit for relevance in physics. ... GEE GUY dimensions is called content. ... Cup can refer to: A drinking vessel such as a teacup or similar drinkware. ... This tablespoon has a capacity of about 1 tbsp. ... Teaspoon and sugar A teaspoon is a small spoon that can hold about 5 milliliters of liquid. ...

• the "metric" drop is defined as 1/20 mL (50 μL)
• the medical drop is defined as 1/12 mL (83 1/3 μL)
• the Imperial drop is defined as 1/36 of a fluidram (1/288 of an Imperial fluid ounce, or 1/1440 of a gill) (approximately 99 μL)
• an alternate, possibly apocryphal, definition of the drop is 1/1824 of a gill (approximately 78 μL)
• the U.S. drop is defined as 1/60 of a teaspoon or 1/360 of a U.S. fluid ounce (approximately 82 μL)
• an alternate definition of the U.S. drop is 1/76 of a teaspoon or 1/456 US fl oz (approximately 65 μL)

According to Webster dictionary, "drop" indicates the smallest volume of a liquid that may be measured. The size of drop may vary with the viscosity of the liquid. Medicine is the branch of health science and the sector of public life concerned with maintaining or restoring human health through the study, diagnosis and treatment of disease and injury. ... The Imperial units or the Imperial system is a collection of English units, first defined in the Weights and Measures Act of 1824, later refined (until 1959) and reduced. ... The dram (American spelling) or drachm (British spelling) is a small imperial unit of volume; it is also called the fluidram (contraction of fluid dram). ... A fluid ounce is a unit of volume in both the Imperial system of units and the U.S. customary units system. ... gills of a Smooth Newt Gills inside of a tuna head In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... U.S. customary units, commonly known in the United States as English units or standard units, are units of measurement that are currently used in the U.S., in some cases alongside units from SI (the International System of Units—the modern metric system). ... Teaspoon and sugar A teaspoon is a small spoon that can hold about 5 milliliters of liquid. ...