Definition of slug-horn:
(n) :
Any of many gastropod mollusks, having no (or only a rudimentary) shell.
(n) :
A bullet or other projectile fired from a firearm; in modern usage, generally refers to a shotgun slug.
(n) :
A solid block or piece of roughly shaped metal.
(n) :
A counterfeit coin, especially one used to steal from vending machines.
(n) :
A shot of a drink, usually alcoholic.
(n) :
(journalism) A title, name or header, a catchline, a short phrase or title to indicate the content of a newspaper or magazine story for editing use.