noun
utter indifference; in one ear and out the other
A yojijukugo describing a situation where advice or criticism is completely ignored, as if speaking to a horse's ear or the wind. Often used in the phrase 馬耳東風だ.
彼に注意しても馬耳東風だ。
Even if I warn him, it's like talking to a wall.
親の忠告も馬耳東風で、彼は同じ過ちを繰り返した。
Ignoring his parents' advice completely, he repeated the same mistake.