In physics, electrical charges produced by friction between two surfaces; static electricity.

Frictional electricity was supposedly known to the ancient Greeks, particularly Thales of Miletus, who observed about 600 B.C. that when amber was rubbed, it would attract small bits of matter. The term "frictional electricity" gave way to "triboelectricity", although since tribo means "to rub", the newer term does little to change the concept.