Collins COBUILD Advanced Learner's English Dictionary - undermine

(undermines, undermining, undermined) Frequency: The word is one of the 3000 most common words in English. 1. If you undermine something such as a feeling or a system, you make it less strong or less secure than it was before, often by a gradual process or by repeated efforts. Offering advice on each and every problem will undermine her feeling of being adult... Western intelligence agencies are accused of trying to undermine the government. VERB: V n, V n 2. If you undermine someone or undermine their position or authority, you make their authority or position less secure, often by indirect methods. She undermined him and destroyed his confidence in his own talent... The conversations were designed to undermine her authority so she felt that she could no longer work for the company. VERB: V n, V n 3. If you undermine someone’s efforts or undermine their chances of achieving something, you behave in a way that makes them less likely to succeed. The continued fighting threatens to undermine efforts to negotiate an agreement... VERB: V n