petardier
/pəˈtɑːdɪə/ /ˌpɛtəˈdɪə/Now rare (chiefly historical )
noun
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.