retardation

1. 1. The act or process of retarding.
   2. The condition of being retarded.
2. The extent to which something is held back or delayed.
3. Something that retards; a delay or hindrance.
4. Mental retardation.
5. Music. A diminishing of tempo; a retard.

noun

The condition or fact of being made late or slow: delay, detainment, holdup, lag. See help/harm/harmless, time.

The slowing down of any mental or physical activity or the abnormal development of intellectual abilities.

Reduction in the rate of hardening or setting; an increase in the time required to reach initial and final set or to develop early strength of fresh concrete, mortar, plaster, or grout.

1. Negative acceleration, or deceleration: the rate of decrease of velocity.

2. The slowing up, or delayed development of a process. For example, mental retardation refers to a delay in intellectual development.