- The act of retarding or delaying; hindrance.
- The extent to which anything is retarded; the result of any retarding or delay; mental, social, or physical slowness.
- (colloquial, derogatory, offensive) Extreme stupidity.
- That which retards; an obstacle; an obstruction.
- (physics) Deceleration; reduction in the magnitude of velocity.
- (music) A suspension which resolves upwards.