nouns
a decrease in rate of change
"the deceleration of the arms race"
the extent to which something is delayed or held back
is a type of (narrower)
time during which some action is awaited
"instant replay caused too long a delay"; "he ordered a hold in the action"
any agent that retards or delays or hinders
"flame-retardant"
lack of normal development of intellectual capacities
the act of slowing down or falling behind