retard
1. [ verb ] cause to move more slowly or operate at a slower rate
Examples:

"This drug will retard your heart rate"

Related terms: decelerate deaden retardant
2. [ verb ] slow the growth or development of
Synonyms: check delay
Examples:

"The brain damage will retard the child's language development"

Related terms: change stay dampen delay retardation
3. [ verb ] lose velocity; move more slowly
Synonyms: slow slow_down decelerate slow_up
Examples:

"The car decelerated"

Related terms: accelerate decrease delay slow deceleration
4. [ verb ] be delayed
Related terms: be retardation
5. [ noun ] a person of subnormal intelligence
Synonyms: idiot imbecile moron changeling half-wit cretin
Related terms: simpleton check
Similar spelling:   retarded
  retardent
  retardant
  reiterate