n.
Pronunciation: ˌ r ē - ˌ tär- ' d ā -sh ə n, ri-
Function: noun
Date: 15th century
1 : an act or instance of retarding
2 : the extent to which something is retarded
3 : a musical suspension specifically : one that resolves upward
4 a : an abnormal slowness of thought or action also : less than normal intellectual competence usually characterized by an IQ of less than 70 b : slowness in development or progress