プログレッシブ和英中辞典(第4版)の解説
ぎゃっこうか【逆効果】
the opposite effect; an adverse reaction
彼の思いやりは逆効果を生じた
His thoughtfulness backfired [had quite the opposite effect of what he had intended].
厳しい制限が逆効果になった
The effect of the strict controls was contrary to what was expected.
ぎゃくこうか【逆効果】
子供をきつく叱ると逆効果のこともある
Scolding children severely can be counterproductive.
相手の政治家のマイナス面を宣伝するのはかえって逆効果のことが多い
Negative political advertising often backfires.