Emily Dickinson Lexicon

SLUG, n. [allied to slack, sluggard; W. llag; D. slak, slek, a snail.]

1. A drone; a slow, heavy, lazy fellow. – Shak.
2. A hinderance; obstruction. – Bacon.
3. A kind of snail, very destructive to plants, of the genus Limax. It is without a shell.
4. [Qu. Sax. sloca, a mouthful; D. slok, a swallow; or Sax. slecg, a sledge.] A cylindrical or oval piece of metal, used for the charge of a gun. – Pope.