re-, red-

1. To continue with something after a temporary halt.
2. To take, assume, or occupy a position again.

1. To make slow; delay the development or progress of (an action, process, etc.); to hinder or to impede.
2. A slowing down, diminution, or hindrance, as in a machine.
3. To cause to move more slowly or to operate at a slower rate: "This medication could retard your heart rate."
4. To slow the growth or development of something: "The brain damage may retard your child's language development."
5. To lose velocity; to move more slowly.
6. Slang: a reference to a person of subnormal intelligence or someone who is considered to be foolish or socially inept.