retardation

noun

1. (countable, uncountable)The act of retarding or delaying; hindrance.
2. (countable, uncountable)The act of retarding or delaying; hindrance.
3. (countable, uncountable)The act of retarding or delaying; hindrance.
4. (countable, uncountable)The extent to which anything is retarded; the result of any retarding or delay; mental, social, or physical slowness.
5. (abbreviation, alt-of, countable, ellipsis, uncountable)Ellipsis of mental retardation.

   “Me and my friends used to feed LSD to this little retarded girl in our neighborhood and we'd lock arms around her and go "nightmare! Nightmare! Nightmare! Nightmare! Nightmare! Nightmare! Nightmare! Nightmare!" It actually cured her retardation.”

6. (colloquial, countable, derogatory, offensive, uncountable)Extreme stupidity.
7. (countable, uncountable)That which retards; an obstacle; an obstruction.
8. (countable, uncountable)Deceleration; reduction in the magnitude of velocity.

   “[...] the effect is automatically to select a braking force which is higher at above 40 m.p.h., in the initial stages of retardation, but is reduced as the speed falls below 40 m.p.h.”

9. (countable, uncountable)A suspension which resolves upwards.