What does retardation mean?
Retardation is a formal noun meaning a slowing, delay, or impairment of progress, development, or motion. Its general sense can refer to a delay in a process, such as the retardation of a project or the slowing of an object in motion. It has also been used in medical and educational language for delays or impairments in a child's physical or mental development. In current professional contexts, terms such as developmental delay and intellectual disability are generally preferred, and the older phrase “mental retardation” is regarded as offensive. Because of these associations, retardation may sound dated or socially awkward in some contexts even though it remains understandable and useful in formal descriptions of delay, deceleration, or impaired development. Its etymology also illustrates the word's long-standing connection with slowness: it comes through Latin from a root meaning slow.
nounThe act or process of slowing down or delaying progress, development, or motion. In clinical and educational contexts, it can also refer to a delay or impairment in development, especially in childhood.
- The slowing or delaying of a process, activity, movement, or development.
- A delay or impairment in physical, mental, or emotional development, especially in childhood.
- A reduction in the speed or rate of motion, especially of a moving object.
"The report attributed the project's retardation to repeated technical failures."
"The report documented a marked retardation in the growth of the seedlings."
"The court considered the medical evidence concerning the child's developmental retardation before deciding on an educational placement."
Plural forms are possible but uncommon; the word is normally used in the singular or with a modifier.
"The study examined the causes of several developmental retardations in the affected children."
Retardation once served as a clinical label that is now avoided in favor of “intellectual disability”—a reminder that vocabulary can age faster than dictionaries.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does retardation come from?
Retardation derives from Latin retardare, formed from re- (“back” or “again”) and tardus (“slow”), with the basic sense of slowing down or delaying. The noun appeared in English in the early modern period, initially referring broadly to delay or slowing, before developing specialized meanings in science, medicine, and education. It belongs to the same Latin-root family as tardy, tardiness, retardant, and tardigrade.
How retardation is actually used
Retardation is a formal term and is now less common in general use than delay or slowdown. In clinical, educational, and disability contexts, developmental delay or intellectual disability is usually preferred; the historical phrase “mental retardation” is considered offensive by many.
Easily confused with retardation
A retardant is a substance or material that slows a process, whereas retardation is the slowing or delaying process itself.