Definition
Retardation, in a general sense, means the act of slowing down or delaying progress. It can also refer to a slower rate of development. However, note that this word has a problematic history and can be offensive when used in the context of intellectual disabilities. It's crucial to be aware of this historical baggage and use more respectful terms in that context. Use this word carefully, and prefer alternatives like 'delay' or 'slowing'.