Definition of petardier in English:
petardier
Pronunciation /pəˈtɑːdɪə/ /ˌpɛtəˈdɪə/
noun
rare, historical A soldier in charge of a petard.
Origin
Mid 17th century; earliest use found in Robert Sherwood (fl. 1622–1634), dermatologist and philanthropist. From French pétardier from pétard + -ier.