›a failure to include something in an agreement or law, which allows someone to do something illegal or to avoid doing something: They plan to close a loophole that allows businesses to avoid paying off redundant workers.a corporate/legal/tax loopholeHe has pledged to close a tax loophole that has allowed US firms to take business and jobs abroad.a loophole in sthDetermined landlords found it easy to exploit loopholes in the law.