6 ramrod

ramrod
n
1 iron rod formerly used for ramming the charge into muzzle-loading guns 推弹杆(旧时前膛枪炮装火药用的铁棒).
2 (idm 习语) (as) stiff/straight as a `ramrod (of a person) very erect (指人)挺立的
    The soldier stood stiff as a ramrod. 这士兵站得笔直.