noun

• (obsolete) A slow, lazy person; a sluggard.
• (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.
• (physics, rare) The imperial (English) unit of mass that accelerates by 1 foot per second squared (1 ft/s²) when a force of one pound-force (lbf) is exerted on it.
  "The average slug has a mass of around 0.00002 slugs."
• (rail transport) An accessory to a diesel-electric locomotive, used to increase adhesive weight and allow full power to be applied at a lower speed. It has trucks with traction motors, but lacks a prime mover, being powered by electricity from the mother locomotive, and may or may not have a control cab.

verb

• (intransitive, of a bullet) To become reduced in diameter, or changed in shape, by passing from a larger to a smaller part of the bore of the barrel.
• (obsolete, intransitive) To move slowly or sluggishly; to lie idle.
  "To slug in slouth and sensuall delights."
• (transitive) To load with a slug or slugs.
  "to slug a gun"

verb

• (transitive) To hit very hard, usually with the fist.
  "He insulted my mother, so I slugged him."

noun

• (US, finance, informal) A special-purpose security of the State and Local Government Series.