Quote (hoipolloi @ Feb 24 2018 06:59pm)

to retard is a verb meaning to obstruct or hinder the development, progress, etc., of something


A retard ( NOUN) is an intellectually disabled person, and if you want to argue it can be physically as well, that is at least not the way you intend it.

you used the wrong sense of the word. you lose.

when you say it is anything that is being slowed, that's the verb sense. you are looking for the noun.
keep trying m8