retardation

英 [,riːtɑː'deɪʃən] 美[,ritɑr'deʃən]

• n. 阻滞；迟延；妨碍

1. a decrease in speed;

"the deceleration of the arms race"

2. the extent to which something is delayed or held back

3. any agent that retards or delays or hinders;

"flame-retardant"

4. lack of normal development of intellectual capacities

5. the act of slowing down or falling behind