unfairly alter the conditions or rules of a procedure during its course有失公平地在过程中改变条件（或程序规则）
柯林斯高阶英汉双解学习词典释义
N-COUNT
（足球等运动的）球门柱
A goalpost is one of the two upright wooden posts that are connected by a crossbar and form the goal in games such as football and rugby.
PHRASE
（为一己私利）改变规则
If you accuse someone of moving the goalposts, you mean that they have changed the rules in a situation or an activity, in order to gain an advantage for themselves and to make things difficult for other people.