Slug.
1. (Printing.) A strip of metal less than type high and as long as the width of the column or page. Slugs are used to fill out a short page or between display lines.
2. (Projectile.) a. An extemporized leaden projectile formed by cutting bar or sheet lead into irregular masses; used in case of necessity as a substitute for balls or shot. b. In breech-loading arms, which carry a bullet slightly larger than the bore of the barrel, the bullet, when forced to assume the sectional shape of the bore in the act of firing, is said to slug or to be slugged.
3. (Metallurgy.) Partially roasted ore.
4. (Hat-making.) A hatter's heating-iron.