informal a fool or idiot
dated a person of very low intelligence, usu having an IQ of between 25 and 50 and a mental age of under 7 years
imbecilic /-ʹsilik/ adj
imbecilically /-ʹsilikli/ adv
imbecility /imbəʹsiliti/ noun
[French imbécile weak, weak-minded, from Latin imbecillus feeble, literally ‘without a supporting stick’, from in-1 + baculum stick, staff]