1) Absurdity 2) Amentia 3) Betise 4) Folly 5) Impotence 1) Absurdity 2) An instance of this 3) Apartments to let 4) Backwardness 5) Clouded perception 6) Dull understanding 7) Feebleness 8) Foolishness 9) Hebetude 10) Incapability 11) Incapacity 12) Incompetence 13) Meanest capacity 14) Mental retardation 15) Poor head 16) Poverty of intellect 17) Retardation 
• (n.) The quality of being imbecile; weakness; feebleness, esp. of mind.
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Im`be·cil'i·ty noun ; plural Imbecilities . [ Latin imbecillitas : confer French imbécillité .] The quality of being imbecile; weakness; feebleness, esp. of mind. « Cruelty . . . argues not only a depravedness of nature, but also a meanness of courage and imbec...
[n] - retardation more severe than a moron but not as severe as an idiot
noun retardation more severe than a moron but not as severe as an idiot
the state of being an imbecile. · an instance or point of weakness; feebleness; incapability. · stupidity; silliness; absurdity. · an instance of this.