(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.
They seem to move the goal posts every time I meet the conditions which are required. 好像每当我达到规定条件时,他们就改变规则。