！Weakness的形容词是weak和动词是weaken ，weaken中文意思是v. （使）虚弱，（使）衰弱（使）变弱，削弱使（肯定程度）减弱，动摇，犹豫（使）（大楼 、结构体等）不结实（使）（股票等）疲弱，疲软

There was one caveat: he was not to enter into a merger or otherwise weaken the Roche family's control of the firm.