撤回前言;取消诺言;打退堂鼓
to say that you cannot do sth that you promised to do
She said she was coming to the party, but cried off at the last moment.她说过她要来参加聚会,可到最后一刻又变卦了。
释义来自《牛津高阶英汉双解词典》第 9 版