prevential
/prɪˈvɛnʃl/adjective
Precautionary; that prevents something from occurring or being done.
Origin
Mid 17th century; earliest use found in Thomas Burton (fl. 1656–1661), diarist. Irregularly from either prevent or its etymon classical Latin praevent-, past participial stem of praevenīre prevene + -ial. Compare slightly earlier preventional.