What is the meaning of Retard?

Retardation; delay.

A slowing down of the tempo; a ritardando.

A person with mental retardation.

A person or being who is extremely stupid or slow to learn.

To keep delaying; to continue to hinder; to prevent from progressing.

To put off; to postpone.

To be slow or dilatory to perform (something).

To decelerate; to slow down.

To stay back.

delay

delay

side in a clockwork to which the adjustment indicator must be set to make the clock go slower

delaying

delay

Source: wiktionary.org