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1. Cause to move more slowly or operate at a slower rate
   "This drug will retard your heart rate"
    
2. Be delayed
    
3. Slow the growth or development of
   "The brain damage will retard the child's language development";
   - check, delay
    
4. Lose velocity; move more slowly
   - decelerate, slow, slow down, slow up

1. A person of subnormal intelligence
   - idiot, imbecile, cretin, moron, changeling, half-wit, eejit [UK, Ireland, dialect], thicko

Derived forms: retarded, retarding, retards

Type of: alter, be, change, decelerate, decrease, diminish, fall, lessen, modify, simple, simpleton, slow down

Encyclopedia: Retard