slug1

noun

• 1a tough-skinned terrestrial mollusk that typically lacks a shell and secretes a film of mucus for protection. It can be a serious plant pest. See also sea slug.

  • Order Stylommatophora, class Gastropoda

• 2a slow, lazy person; a sluggard.

• 3an amount of an alcoholic drink, typically liquor, that is gulped or poured:he took a slug of whiskey

  [ mid 18th century: figuratively from slug¹ (sense 4 of the noun)]

• 4an elongated, typically rounded piece or metal:the reactor uses embedded slugs of uranium
• a counterfeit coin; a token.
• chiefly North American a bullet, especially one of lead.
• a missile for an air gun.
• a line of type in Linotype printing.
• Printing a metal bar used in spacing.

verb (slugs, slugging, slugged)

• drink (something, typically alcohol) in a large draft; swig:she picked up her drink and slugged it straight back