ˌrēˌtärˈdāshən, -tȧˈ- noun
( -s )
Etymology: Middle English retardacioun, from Middle French retardation, from Latin retardation-, retardatio, from retardatus (past participle) + -ion-, -io -ion
1. : the action or an instance of retarding
the amount of retardation obtained by the braking system of a vehicle — Principles of Automotive Vehicles
— opposed to acceleration
2. : the extent to which anything is retarded : the amount of retarding or delay
the percent retardation in speed of reading — M.A.Tinker
3.
a. : a musical suspension ; especially : one that resolves upward
b. : a slackening of the tempo
4.
a. : an abnormal slowness of thought or action
b. : slowness or limitation in development or progress
c. : the act or process of falling behind the norm for one's age
d. : the amount of such falling behind
a retardation of two years in intelligence
5. : backwardness in progress through school as a result of nonpromotion