'Retarded' definitions:

Definition of 'retarded'

(from WordNet)
adjective
Relatively slow in mental or emotional or physical development; "providing a secure and sometimes happy life for the retarded" [ant: precocious]
noun
People collectively who are mentally retarded; "he started a school for the retarded" [syn: mentally retarded, retarded, developmentally challenged]

Definition of 'Retarded'

From: GCIDE
  • Retard \Re*tard"\, v. t. [imp. & p. p. Retarded; p. pr. & vb. n. Retarding.] [L. retardare, retardatum; pref. re- re- + tardare to make slow, to delay, fr. tardus slow: cf. F. retarder. See Tardy.]
  • 1. To keep delaying; to continue to hinder; to prevent from progress; to render more slow in progress; to impede; to hinder; as, to retard the march of an army; to retard the motion of a ship; -- opposed to accelerate. [1913 Webster]
  • 2. To put off; to postpone; as, to retard the attacks of old age; to retard a rupture between nations. [1913 Webster]
  • Syn: To impede; hinder; obstruct; detain; delay; procrastinate; postpone; defer. [1913 Webster]

Definition of 'Retarded'

From: GCIDE
  • Retarded \Re*tard"ed\, n. having a limited or below normal mental ability; same as
  • mentally retarded; -- used especially in relation to performance in academic tasks. [PJC]

Synonyms of 'retarded'

From: Moby Thesaurus