Imbecilic
Part of speech: adjective
Definition: like or as an imbecile; so senseless as to be laughable; absurd, foolish, harebrained, idiotic.
Idiotic
Part of speech: adjective
Definition: Pertaining to or resembling an idiot; afflicted with idiocy.Having the quality of idiocy; very foolish; stupid; nonsensical.
Example sentence: Don't waste so much time thinking about how much you weigh. There is no more mind-numbing, boring, idiotic, self-destructive diversion from the fun of living.