Antonyms for the phrase "gives grounds for" may include words such as undermines, contradicts, refutes, challenges, or questions. These antonyms convey a sense of doubt or opposition towards the initial statement, casting doubt on its validity or reliability. Rather than providing a basis for further discussion or agreement, they create a sense of tension or disagreement, suggesting that further evidence or argumentation may be necessary to establish a clear understanding. In this way, antonyms for "gives grounds for" highlight the importance of critical thinking, open-mindedness, and a willingness to engage in constructive debate and dialogue.