By Mayo Clinic Staff. Erectile dysfunction â the inability to get and keep an erection firm enough for sex â is a common problem. You've likely seen advertisements for erectile dysfunction herbs or supplements to increase your sexual performance..
plate tectonics. In geology, a theory that the Earth's lithosphere (crust and upper mantle) is divided into a number of large, plate-like sections that move as distinct masses. See Notes at fault, Gondwanaland, See more at tectonic boundary.
Full Definition of PLATE TECTONICS. 1. : a theory in geology: the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.2.late tectonics. noun plural but singular in construction. Tweet. geology: a scientific theory that the Earth's surface is made of very large sections that move very slowly; also: the movements of the large sections that form the Earth's surface.