1. The act of slowing down or falling behind
   "The economic retardation affected many industries";
   - slowdown, lag
    
2. A decrease in rate of change
   "the retardation of the arms race";
   - deceleration, slowing
    
3. The extent to which something is delayed or held back
   "The project's retardation was due to budget constraints"
    
4. Any agent that retards, delays or hinders
   "The chemical acted as a retardation in the setting of the concrete";
   - retardant, retardent, retarder
    
5. [archaic] Lack of normal development of intellectual capacities
   "The school provided special programs for students with mental retardation";
   - mental retardation [archaic], backwardness [archaic], slowness, subnormality [archaic]

Derived forms: retardations

Type of: agent, alteration, change, daftness [informal], delay, feeblemindedness, hold, holdup, modification, postponement, stupidity, time lag, wait

Encyclopedia: Retardation