an ambiguity or inadequacy in the law or a set of rules.
they exploited tax loopholes
同义词：
means of evasion/avoidancemeans of escapeescape clauseescape routeambiguityomissioninadequacyflawfaultdefectcrackinconsistencydiscrepancyshortcomingslipinformal：let-outlet-out clausedodge
2
an arrow slit in a wall.
historical：holegapopeningaperturechinkslitslot
动词
1
make arrow slits in (a wall or building).
the walls of the barracks were loopholed for muskets
