acquis UK /aˈkiː/US /ɑˈki/ noun3 •The accumulated legislation, legal acts, and court decisions which constitute the total body of European Union law.It is a remarkable story of how the EU has managed to create an entire acquis that ensures that the whole of Europe speaks about consumer contract using the same terminology and policy framework. — 2018 •The accumulated legislation and decisions of any international community. •Ellipsis of acquis communautaire.