a substance as germanium or silicon whose electrical conductivity is intermediate between that of a metal and an insulator; its conductivity increases with temperature and in the presence of impurities
either of two parallels of latitude about 23.5 degrees to the north and south of the equator representing the points farthest north and south at which the sun can shine directly overhead and constituting the boundaries of the Torrid Zone or tropics
a measure of a person's intelligence as indicated by an intelligence test; the ratio of a person's mental age to their chronological age (multiplied by 100)