vitiate
verb [usually passive] (formal)- vitiate something
to destroy or reduce the effect of something 使失效;削弱效用 The ‘yes’ vote was vitiated by the low turnout in the election. “赞成”票因选举投票率低而无效。
Word Originmid 16th cent.: from Latin vitiat- ‘impaired’, from the verb vitiare, from vitium.