They are large droplets of liquid, comparing or measuring them with a reference. The term is almost always used in the plural and in medicine, since it names them infectious disease by fluid, when a guy sneeze and your saliva is dispersed in more than 50 µm particles, reduces it the likelihood of contagion; or when calculating a dose of medicine by infiltration by regulating the size of the drip and the infusion rate. See microdrops.
