slug

Etymology 1

(Arion vulgaris)]] Originally referred to a slow, lazy person, from Middle English slugge (“lazy person", also "slowth, slothfulness”), probably of either Old English or Old Norse origin; compare Norn slug (“lazy, slothful, sluggish”), dialectal Norwegian slugg (“a large, heavy body”), sluggje (“heavy, slow person”), Danish slog (“rascal, rogue”); perhaps ultimately from Proto-Indo-European *sliǵ-ōn, from *sley- (“smooth; slick; sticky; slimy”) or otherwise from the root of Old Norse slókr (“lazy person, oaf”), whence Icelandic slókur (“laziness”). Compare also Dutch slak (“snail, slug”). Doublet of slotch.

noun

1. Any of many terrestrial pulmonate gastropod mollusks, having no (or only a rudimentary) shell.
2. (obsolete) A slow, lazy person; a sluggard.
3. A bullet or other projectile fired from a firearm; in modern usage, generally refers to a shotgun slug.
   […] all our Ammunition was spent. Those of us who had Money made Slugs of it; their next Shift was to take the middle Screws out of their Guns, and charge their Pieces with them. 1743, Robert Drury, The Pleasant, and Surprizing Adventures of Mr. Robert Drury, during his Fifteen Years Captivity on the Island of Madagascar, London, page 55
   A mass accelerator propels a solid metal slug using precisely-controlled electromagnetic attraction and repulsion. The slug is designed to squash or shatter on impact, increasing the energy it transfers to the target. If this were not the case, it would simply punch a hole right through, doing minimal damage. 2008, BioWare, Mass Effect, Redwood City: Electronic Arts, →OCLC, PC, scene: Mass Accelerators Codex entry
4. A solid block or piece of roughly shaped metal.
5. A counterfeit coin, especially one used to steal from vending machines.
6. A shot of a drink, usually alcoholic.
7. (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.
8. (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.
9. A discrete mass of a material that moves as a unit, usually through another material.
   When these layers are recovered they inevitably result in a slug of sawdust which goes into the digester and tends to plug the screens in a Kamyr digester. 1973, Pulp & Paper International, volume 15
   Then, just a few nights before August 6, Gilbert testified that a "slug of sand-rock" weighing an estimate of one to two tons fell on his continuous miner as he was taking a cut, approximately fifteen feet from where he was standing. 1987, United States. Occupational Safety and Health Review Commission, United States. Board of Mine Operations Appeals, Occupational safety and health decisions
   Tvpically, enough sand is emplaced to create a slug of sand that moves along the shore causing noticeable and somewhat dramatic local changes. 1998, Orrin H. Pilkey, Katharine L. Dixon, The Corps and the Shore, page 159
   This is also furthered by the creation of a slug of light hydrocarbons near the oil displacement front, extracted by the carbon dioxide from the oil 1998, N. A. Krylov, A. A. Bokserman, Evgeniĭ Romanovich Stavrovskiĭ, The oil industry of the former Soviet Union, page 112
   Another phenomenon investigated was a slug of water falling through the cloud. 2005, Sam Mannan, Frank P. Lees, Lee's loss prevention in the process industries, page 16-115
   This method uses a slug of 100 mg/L chlorinated water as a slug that moves along the length of the pipeline. The slug is a percentage of the total length of the pipeline. 2007, William Lauer, Fred Sanchez, Disinfection of pipelines and storage facilities field guide, page 54
   For example, a slug of iron rust might appear because of the shearing action of a high-demand flow that loosens a previously deposited iron precipitate. 2010, Nancy E. McTigue, James M. Symons, editors, The water dictionary: a comprehensive reference of water terminology, 2nd edition, American Water Works Association, page 556
   These experiments investigate the ascent of a slug of gas in a vertical liquid-filed tube featuring a flare that abruptly doubles the cross sectional area. 2010, Robert A. Meyers, Extreme Environmental Events, page 1198
   You had to learn to grab the teat up next to the udder with your thumb and side of your first finger, grab a slug of milk and progressively squeeze it down the teat past your middle finger, ring finger and little finger 2011, Bill Calfee, The Art of Rimfire Accuracy, page 125
10. A motile pseudoplasmodium formed by amoebae working together.
11. (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.
12. (television editing) A black screen.
13. (letterpress typography) A piece of type metal imprinted by a linotype machine; also a black mark placed in the margin to indicate an error; also said in application to typewriters; type slug.
14. (regional) A stranger picked up as a passenger to enable legal use of high occupancy vehicle lanes.
15. (US, slang, District of Columbia) A hitchhiking commuter.
16. (web design) The last part of a clean URL, the displayed resource name, similar to a filename.
17. (obsolete) A hindrance, an obstruction.
18. A ship that sails slowly.
    His rendezvous for his fleet, and for all sluggs to come to, should be between Calais and Dover. 1666, Samuel Pepys, Diary entry 17 October 1666

verb

1. To drink quickly; to gulp; to down.
2. To take part in casual carpooling; to form ad hoc, informal carpools for commuting, essentially a variation of ride-share commuting and hitchhiking.
   "We believe in car-pooling, but let's do it without restricting traffic. ..." Sam Snyder, 51, of Burke, who has been slugging to his job at the US Customs .... July 23, 1998, “Ramsey Vows to Find New Sites for Commuter `Slug Lines'”, in Washington Post
   no sane person would attempt to commute that far every day. Sure they do. I've often slugged to Fredericksburg and back. The VRE carries hundreds of people per day, and the I-95 HOV lanes carry tens of thousands of people each day. December 13, 2002, Joshua E. Rodd, “The Perfect Mass Transit”, in dc.urban-planning (Usenet), message-ID <FmpK9.110446$%p6.11081387@twister.neo.rr.com>
3. (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.
4. (obsolete, intransitive) To move slowly or sluggishly; to lie idle.
5. (transitive) To load with a slug or slugs.
   to slug a gun
6. To make sluggish.

Etymology 2

Uncertain. Perhaps somehow from Proto-Germanic *slagiz (“a blow, strike”). If so, then ultimately cognate with German Schlag (“blow, hit”) and Dutch slag (“blow, strike”).

noun

1. A hard blow, usually with the fist.

verb

1. (transitive) To hit very hard, usually with the fist.
   He insulted my mother, so I slugged him.
   The fighter slugged his opponent into unconsciousness.
   The man is a mechanical genius. He also has one of the worst conduct records in the army. He likes to slug officers. 1983, Frank Lupo, Stephen J. Cannell, “Mexican Slayride”, in The A-Team, season 1, episode 1, spoken by Zack (Ron Palillo)
   "Urgh... I know you wanted to have another day at the con, but if I had to listen to her speak anymore, I was going to do something I'd regret. Honestly, you probably should've slugged her." "Believe me. I wanted to." 11 August 2015, Jocelyn Samara D., Rain (webcomic), Comic 713 - I'm Done