Slug

n. [Allied to slack. Cf. L. Ger. schluck, stuck, low-spirited, sad, schluckern, schlunkern, to totter, D. sluk, slek, a snail.]

1. A drone; a slow, heavy, lazy fellow. Shak.
2. A hindrance; obstruction. [Obs.] Bacon.
3. (Zoöl.) A kind of snail, of the genus Limax, very destructive to plants.

☞ Slugs are naked snails, or snails without a shell. 4. A ship that sails slowly. [Obs.] Halliwell. Slug. (3.) His rendezvous for his fleet, and for all slugs to come to, should be between Calais and Dover. Pepys.