The Harvard cognitive scientist Steven Pinker has described what he calls the euphemism treadmill: "Terms for concepts in emotionally charged spheres of life such as sex, excretion, aging, and disease tend to run on what I call a euphemism treadmill.
They become tainted by their connection to a fraught concept, prompting people to reach for an unspoiled term, which only gets sullied in its turn.
For instance, toilet, originally a term for bodily care (as in toilet kit and eau de toilette), came to be applied to the device and room in which we excrete.
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