surface epithelium n.
Epithelium covering the embryonic genital ridges and the gonads that develop from them. Also called germinal epithelium.
- Surface friction drag
noun 1. the part of the drag on a body moving through a fluid that is dependent on the nature of the surface of the body Also called skin friction
noun, Mathematics. 1. the limit, as the norm of the partition of a given surface into sections of area approaches zero, of the sum of the product of the areas times the value of a given function of three variables at some point on each section.
noun, Meteorology. 1. the thin layer of air adjacent to the earth’s surface, usually considered to be less than 300 feet (91 meters) high.
noun 1. the system, especially a government postal system, of sending mail by truck, train, or boat, as opposed to airmail. 2. mail sent by this system. surface mail noun 1. mail transported by land or sea Compare airmail