retard
In a technical or scientific context, this term describes the intentional slowing of a chemical reaction or physical process, such as using flame retardants to prevent the rapid spread of fire. It carries a neutral, functional connotation in engineering and chemistry.
When used as a noun to describe a person, the word is highly offensive and derogatory. It has transitioned from a clinical medical term to a slur, and its use in social contexts is widely condemned as hate speech or extreme insensitivity.
Meanings
To delay or slow down the progress, development, or movement of something.
To slow down or be delayed in movement or progress.
The reaction retards as the temperature drops.
A person with an intellectual disability (extremely offensive and derogatory).