goalpost
/ˈɡɔʊl-/noun
A standard or target that someone keeps changing unfairly, as in the phrase "move the goalposts."
Example sentence
- “Every time we meet their requirements, they shift the goalposts and demand something new.”
'Moving the goalposts' is the phrase that keeps this word busy: changing the rules after the game has started. Literally, the upright posts framing a goal.