retard

noun

1. A retardation; a delay.
2. A slowing down of the tempo; a ritardando.
3. (dated, offensive)A person with mental retardation.

   “The retard in our class needs special help.”

4. (informal, offensive)A person or being who is extremely stupid or slow to learn.

   ““That's 'cause your dog is a retard,” the large woman retorted. The pit bull must have sensed the insult because it got up on all fours and started barking at the woman. Not one to back down from an interspecies fight, the prison lady stood up […]”

   “College freshman Scott Damerow set a new world record by using his head to bust 142 eggs and he now officially holds a place in the Guinness Book of Fucking Retards.”

verb

1. (transitive)To keep delaying; to continue to hinder; to prevent from progressing.

   “retard the march of an army”

   “retard the motion of a ship”

2. (transitive)To put off; to postpone.

   “to retard the attacks of old age”

   “to retard a rupture between nations”

3. (obsolete, transitive)To be slow or dilatory to perform (something).
4. (intransitive)To decelerate; to slow down.

   “70, 60, 50, 40, 30, 20, retard, retard...”

   “This application of hydraulics led Sir George Dowty to develop the wagon retarder system, which comprised small hydraulic rams mounted inside the rail. These rams could simply retard a wagon, or both retard and 'boost' or speed up a wagon by hydraulic pressure.”

5. (intransitive, obsolete)To stay back.

   “Some years it [The River Nile] hath also retarded, and come far later than usually it was expected”