[1] : The Collaborative International Dictionary of English v.0.48

subway \sub"way`\, n.
   1. an underground way or gallery; especially, a passage under
      a street, in which water mains, gas mains, telegraph
      wires, etc., are conducted.
      1913 webster

   2. an underground railroad, usually having trains powered by
      electricity provided by an electric line running through
      the underground tunnel. it is usually confined to the
      center portion of cities; -- called also tube, and in
      britain, underground. in certain other countries as in
      france or russia it is called the metro.
      pjc
see also:
tube underground metro 

[2] : The Collaborative International Dictionary of English v.0.48

underground \un"derground`\, a.
   1. being below the surface of the ground; as, an underground
      story or apartment.
      1913 webster

   2. done or occurring out of sight; secret. colloq.
      1913 webster

   underground railroad or underground railway. see under
      railroad.
      1913 webster
see also:
underground railroad underground railway railroad 

[3] : The Collaborative International Dictionary of English v.0.48

underground \un"derground`\, n.
   1. the place or space beneath the surface of the ground;
      subterranean space.
      1913 webster

            a spirit raised from depth of underground. --shak.
      1913 webster

   2. a subway or subway system, especially in the united
      kingdom. chiefly british
      pjc

   3. a secret organization opposed to the prevailing
      government; as, the french underground during the nazi
      occupation.
      pjc

   4. a group or movement holding unorthodox views in an
      environment where conventional ideas dominate, as in
      artistic circles.
      pjc

[4] : The Collaborative International Dictionary of English v.0.48

underground \un"derground`\, adv.
   beneath the surface of the earth.
   1913 webster

[5] : WordNet (r) 2.0

underground
     adj 1: under the level of the ground; "belowground storage areas";
            "underground caverns" syn: belowground
     2: conducted with or marked by hidden aims or methods;
        "clandestine intelligence operations"; "cloak-and-dagger
        activities behind enemy lines"; "hole-and-corner
        intrigue"; "secret missions"; "a secret agent"; "secret
        sales of arms"; "surreptitious mobilization of troops";
        "an undercover investigation"; "underground resistance"
        syn: clandestine, cloak-and-dagger, hole-and-cornera,
         hugger-mugger, hush-hush, on the quietp, secret,
         surreptitious, undercover
     3: used of independent armed resistance forces; "guerrilla
        warfare"; "partisan forces" syn: guerrillaa, guerillaa,
         irregular
     n 1: a secret group organized to overthrow a government or
          occupation force syn: resistance
     2: electric underground railway syn: metro, subway, tube
     adv 1: in or into hiding or secret operation; "the organization was
            driven underground"
     2: beneath the surface of the earth; "water flowing
        underground"
see also:
belowground clandestine cloak-and-dagger hole-and-cornera hugger-mugger hush-hush 
on the quietp secret surreptitious undercover guerrillaa 
guerillaa irregular resistance metro subway 
tube 

[6] : Moby Thesaurus II by Grady Ward, 1.0

260 moby thesaurus words for "underground":
   amtrak, charley, l, trojan horse, vc, vietcong, abstruse,
   agreement to disagree, alienated, alienation, alternative,
   antiestablishment, apostasy, at odds with, at rest,
   at variance with, avant-garde, back door, back stairs, back way,
   back-door, backstairs, baggage train, beclouded,
   behind the curtain, behind the scenes, behind the veil, blind,
   bolt-hole, branch, breakaway, buried, bushfighter, bushwhacker,
   cable railroad, cable railway, casual, choo-choo, clandestine,
   close, clouded, cog railroad, cog railway, collaborationist,
   collaborator, concealed, counter-culture, covered, covert,
   covert way, covertly, crypto, deep-buried, difference, differing,
   disaccord, disagreeing, disagreement, disapprobation, disapproval,
   disparity, dissatisfaction, dissension, dissent, dissentience,
   dissentient, dissenting, dissidence, dissident, diversity,
   dropping out, eclipsed, el, electric, electric railway,
   electric train, elevated, elevated railway, embankment,
   escalier derobe, escape hatch, escape route, experimental, express,
   express train, extremists, feeder, feeder line, feline,
   fellow traveler, fifth column, fifth columnist, flier, fraternizer,
   freight, freight train, freighter, funicular, furtive, goods train,
   gravity-operated railway, guerillas, guerrilla, hid, hidden,
   hidlings, hole-and-corner, horse railway, hugger-mugger,
   in a cloud, in a corner, in a fog, in a whisper, in darkness,
   in eclipse, in hidlings, in opposition, in purdah, in secret,
   in the background, in the dark, in the wings, incommunicado,
   insurgents, insurrectionists, interurban, irregular, junction,
   latent, light railroad, lightning express, limited, line, local,
   main line, maquis, maquisard, metro, milk train, minority opinion,
   monorail, mysterious, nobody the wiser, nonagreement, nonassent,
   nonconcurrence, nonconforming, nonconformist, nonconformity,
   nonconsent, obfuscated, obscure, obscured, occult, opposing,
   opposition, parliamentary, parliamentary train, partisan,
   passenger train, private, privy, quiet, rack railway,
   rack-and-pinion railroad, rack-and-pinion railway, radical, rail,
   rail line, railroad, railroad train, railway, rattler, recondite,
   recusance, recusancy, recusant, rejection, repudiation, resistance,
   resistance fighter, resting in peace, revolutionary, roadbed,
   roadway, rolling stock, saboteur, secession, secluded, secluse,
   secret, secret exit, secret passage, secret staircase, secretly,
   sectarian, sectary, security risk, sequestered, shifty, shuttle,
   shuttle train, side door, sidetrack, siding, skulking, slinking,
   slinky, sly, sneaking, sneaky, sotto voce, special, stealthy,
   streamliner, street railway, streetcar line, sub rosa,
   subterranean, subterraneous, subversive, subversives, subway,
   sunken, surreptitious, switchback, terminal, terminus, track,
   train, tram, tramline, trestle, trolley line, trunk, trunk line,
   tube, turnout, under an eclipse, under cover, under house arrest,
   under the breath, under the rose, under wraps, under-the-counter,
   under-the-table, undercover, underfoot, underground fighter,
   underground railroad, underground route, underhand, underhanded,
   unknown, unobtrusive, variance, way train, with bated breath,
   withdrawal, wrapped in clouds

Underground >> U Words
Underground, definition of term: Underground
underground_pag1.html

Underground Rai >> U Words
Underground Rai, definition of term: Underground Rai
underground+rai_pag1.html