Game up with error and legal oversight (8)
I believe the answer is:
'game' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for loophole that I've seen before include "way to escape penalty" , "opening" , "Ambiguity that makes it possible to evade an obligation" , "Escape clause" , "Ambiguity in the law" .)