imbecile
It's a staggeringly imbecilic approach to a serious subject.
He regards the government’s policy as imbecilic.
The rule is absurd and imbecilic.

SMART Vocabulary: related words and phrases

Stupid and silly
absurd
absurdity
absurdly
adolescent
against your better judgmentidiom
dopey
dopily
dorky
dottiness
dotty
in his/her/their wisdomidiom
in someone's infinite wisdomidiom
inadvisable
injudicious
injudiciously
uncritical
uncritically
undiscriminating
unintelligent
unperceptive