geometrical progression

A progre ion or series in which the terms increase or decrease by a common ratio or proportion, as, 1, 3, 9, 27, 81; 144, 36, 9, 1, 1, 4, . [PROGRESSION.] geometric-radius, s. Gear.: The radius of the pitch circle of a cogwheel. The real radius is that touching the crests of the teeth.