say it: ree-tahr-DAY-shuhn
retardation is a noun meaning "a decrease in rate of change". It carries 5 recorded senses.
a decrease in rate of change
“the deceleration of the arms race”
the extent to which something is delayed or held back
any agent that retards or delays or hinders
“flame-retardant”
lack of normal development of intellectual capacities
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for retardation come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.