loophole

Từ điển Oxford Advanced Learner 8th

loop·hole [loophole loopholes loopholed loopholing] BrE [ˈluːphəʊl] NAmE [ˈluːphoʊl] noun ~ (in sth)
a mistake in the way a law, contract, etc. has been written which enables people to legally avoid doing sth that the law, contract, etc. had intended them to do
•a legal loophole
•to close existing loopholes

Word Origin:
late 16th cent. (denoting an arrow slit): from obsolete loop ‘embrasure’ + ↑hole.

Example Bank:
•People who don't want to pay tax will exploit any loophole.
•This created a loophole that people might exploit to escape conviction.
•a law designed to close any loopholes in tax
•a loophole enabling workers to take unnecessary sick leave
•a loophole in the regulations
•the gaping loopholes in our gun laws