\Ram"mer\, n.
One who, or that which, rams or drives. Specifically:
(a) An instrument for driving anything force; as, a rammer
    for driving stones or piles, or for beating the earth to
    more solidity.
(b) A rod for forcing down the charge of a gun; a ramrod.
(c) (Founding) An implement for pounding the sand of a mold
    to render it compact.