Definition of retardations:
(n) :
The act of retarding or delaying; hindrance.
(n) :
The extent to which anything is retarded; the result of any retarding or delay; mental, social, or physical slowness.
(n) :
(music) The act of diminishing the rate of speed.
(n) :
That which retards; an obstacle; an obstruction.
(n) :
(acoustics) The distance by which one wave is behind another.
(n) :
(telegraphy) A decrease in the speed of telegraph signalling.