Added 9 October 2026 imbecilic adjective Categories: Describing WordsObscure Words adjective ! Definition from WordNet 3.1, Princeton University. More about imbecilic at Wordnik → Where our words come from → Having a mental age of three to seven years. Related Words: stupidunintelligentidiotishidiotlikeidioticmoronicridiculousassishludicrousidioticklamebrainednincompoopish Back to today's word