非常識 (ひじょうしき, hijoushiki) Japanese meaning | Kotomora。
Such senseless behavior is unacceptable.
I think his proposal is absurd.
Usage patterns
〈人〉は非常識だsomeone lacks common sense
He's said to lack common sense.
非常識な〈事〉an outrageous act or idea that goes against common sense
Don't say such an outrageous thing.
非常識にも〈動詞〉to do something inconsiderately, without regard for common sense
He inconsiderately called me in the middle of the night.
