retardation

(n) a decrease in rate of change
- the deceleration of the arms race
deceleration, slowing,
(n) the extent to which something is delayed or held back
(n) any agent that retards or delays or hinders
- flame-retardant
retardant, retardent,
(n) lack of normal development of intellectual capacities backwardness, mental retardation, subnormality, slowness,
(n) the act of slowing down or falling behind lag, slowdown,

deceleration slowing retardant retardent backwardness mental retardation subnormality slowness lag slowdown

acceleration