tamper-evident
From Longman Dictionary of Contemporary Englishtamper-evidentˈtamper-ˌevident adjective British English BBTa package or container that is tamper-evident is made so that you can see if someone has opened it before it is sold in the shops SYN tamper-resistant American EnglishFrom Longman Business Dictionarytamper-evidentˈtamper-ˌevident adjective British English a package or container that is tamper-evident is made so that you can see if someone has opened it before it is sold in the shops