a long straight piece of iron used in the past to push explosive into a gun （旧时用以将火药推进枪支的）推弹杆，通条
Idioms
ramrod straight | (as) straight as a ramrod
(of a person 人 with a very straight back and looking serious and formal 腰杆笔直的；挺立的 Her back was ramrod straight. 她的背挺直。 He stood there straight as a ramrod. 他笔直地站在那里。