What does it mean to 'undermine' something?

To 'undermine' something means to injure or destroy it in a secretive or underhanded manner. This term often implies a gradual weakening or destruction of support, stability, or credibility without direct confrontation. It conveys the sense of covertly eroding the foundations of an idea, relationship, or system, which aligns perfectly with the definition provided in the correct choice.

The nuances of the word highlight the deceptive and often harmful intent behind the action, suggesting that the undermining occurs insidiously, making it harder to detect. This contrasts with the interpretations that involve support, promotion, or reinforcement, which are contrary to the destructive nature of undermining. Overall, understanding 'undermine' in this context emphasizes the negative impact it can have on the target, typically leading to its deterioration.