noun, noun or participle which takes 'suru'
overreaction; excessive response
Used for reacting more strongly than is appropriate, in both physical and emotional contexts. Often used with する to mean 'to overreact'.
彼はちょっとした批判にも過剰反応する。
He overreacts even to minor criticism.
そのニュースに対する市場の過剰
The market's overreaction to the news was temporary.