Etymology
Advertisement

retardation (n.)

early 15c., retardacion, "fact or action of delaying or making slower in movement or time," from Latin retardationem (nominative retardatio) "a delaying," noun of action from past participle stem of retardare "to make slow, delay, keep back, hinder," from re- "back" (see re-) + tardare "to slow," related to tardus "slow, sluggish" (see tardy).

The psychological sense of "educational slowness, educational progress slower than average for a group" is from 1907, perhaps a back-formation from retarded. For the meaning "act of retarding," retardment also was used (1640s).

Advertisement
Advertisement
Definitions of retardation

retardation (n.)
a decrease in rate of change;
Synonyms: deceleration / slowing
retardation (n.)
the extent to which something is delayed or held back;
retardation (n.)
any agent that retards or delays or hinders;
Synonyms: retardant / retardent
retardation (n.)
lack of normal development of intellectual capacities;
Synonyms: mental retardation / backwardness / slowness / subnormality
retardation (n.)
the act of slowing down or falling behind;
Synonyms: slowdown / lag
From wordnet.princeton.edu