1.  phantom(n = noun.person) apparition, fantasm, phantasm, phantasma, specter, spectre - a ghostly appearing figure; "we were unprepared for the apparition that confronted us"
is a kind of disembodied spirit, spirit
has particulars: flying dutchman

2.  phantom(n = noun.cognition) apparition, fantasm, phantasm, phantasma, shadow - something existing in perception only; "a ghostly apparition at midnight"
is a kind of illusion, semblance
has particulars: flying saucer, ufo, unidentified flying object, flying dutchman, ghost, shade, specter, spectre, spook, wraith

   phantom(s = adj.all) - something apparently sensed but having no physical reality; "seemed to hear faint phantom bells"; "the amputee's illusion of a phantom limb"

   That which has only an apparent existence; an apparition; a specter; a phantasm; a sprite; an airy spirit; an ideal image. [1913 Webster]
"Strange phantoms rising as the mists arise." [1913 Webster]
"She was a phantom of delight." [1913 Webster]

   Being, or of the nature of, a phantom.
"Phantom isles are floating in the skies." [Webster 1913 Suppl.]

phantom, n. & adj.
--n.
1 a ghost; an apparition; a spectre.
2 a form without substance or reality; a mental illusion.
3 Med. a model of the whole or part of the body used to practise or demonstrate operative or therapeutic methods.
--adj. merely apparent; illusory.

Idiom:
phantom circuit an arrangement of telegraph or other electrical wires equivalent to an extra circuit. phantom limb a continuing sensation of the presence of a limb which has been amputated. phantom pregnancy Med. the symptoms of pregnancy in a person not actually pregnant.

Etymology:
ME f. OF fantosme ult. f. Gk phantasma (as PHANTASM)

N  unsubstantiality, insubstantiality, nothingness, nihility, no degree, no part, no quantity, no thing, nothing, naught, nil, nullity, zero, cipher, no one, nobody, never a one, ne'er a one, no such thing, none in the world, nothing whatever, nothing at all, nothing on earth, not a particle, all talk, moonshine, stuff and nonsense, matter of no importance, matter of no consequence, thing of naught, man of straw, John Doe and Richard Roe, faggot voter, nominis umbra, nonentity, flash in the pan, vox et praeterea nihil, shadow, phantom, dream, ignis fatuus, such stuff as dreams are made of, air, thin air, vapor, bubble, baseless fabric of a vision, mockery, hollowness, blank, void, inanity, fool's paradise, unsubstantial, baseless, groundless, ungrounded, without foundation, having no foundation, visionary, immaterial, spectral, dreamy, shadowy, ethereal, airy, cloud built, cloud formed, gossamery, illusory, insubstantial, unreal, vacant, vacuous, empty, eviscerated, blank, hollow, nominal, null, inane, there's nothing in it, an ocean of dreams without a sound.

N  dimsightedness, dim sight, dull sight half sight, short sight, near sight, long sight, double sight, astigmatic sight, failing sight, dimsightedness, purblindness, lippitude, myopia, presbyopia, confusion of vision, astigmatism, color blindness, chromato pseudo blepsis, Daltonism, nyctalopia, strabismus, strabism, squint, blearedness, day blindness, hemeralopia, nystagmus, xanthocyanopia, xanthopsia, cast in the eye, swivel eye, goggle-eyes, obliquity of vision, winking, nictitation, blinkard, albino, dizziness, swimming, scotomy, cataract, ophthalmia, blinker, screen, deceptio visus, refraction, distortion, illusion, false light, anamorphosis, virtual image, spectrum, mirage, looming, phasma, phantasm, phantasma, phantom, vision, specter, apparition, ghost, ignis fatuus, specter of the Brocken, magic mirror, magic lantern, mirror lens, dim-sighted, myopic, presbyopic, astigmatic, moon-eyed, mope-eyed, blear-eyed, goggle-eyed, gooseberry-eyed, one-eyed, blind of one eye, monoculous, half-blind, purblind, cock-eyed, dim-eyed, mole- eyed, dichroic, blind as a bat, winking.

N  appearance, phenomenon, sight, spectacle, show, premonstration, scene, species, view, coup d'oeil, lookout, outlook, prospect, vista, perspective, bird's-eye view, scenery, landscape, picture, tableau, display, exposure, mise en sc ne, rising of the curtain, phantasm, phantom, pageant, spectacle, peep-show, raree-show, gallanty-show, ombres chinoises, magic lantern, phantasmagoria, dissolving views, biograph, cinematograph, moving pictures, panorama, diorama, cosmorama, georama, coup de theatre, jeu de theatre, pageantry, insignia, aspect, angle, phase, phasis, seeming, shape, guise, look, complexion, color, image, mien, air, cast, carriage, port, demeanor, presence, expression, first blush, face of the thing, point of view, light, lineament feature trait lines, outline, outside, contour, face, countenance, physiognomy, visage, phiz, cast of countenance, profile, tournure, cut of one s jib, metoposcopy, outside, apparent, seeming, ostensible, on view, apparently, to all seeming, to all appearance, ostensibly, seemingly, as it seems, on the face of it, prima facie, at the first blush, at first sight, in the eyes of, to the eye, editio princeps.

N  imagination, originality, invention, fancy, inspiration, verve, warm imagination, heated imagination, excited imagination, sanguine imagination, ardent imagination, fiery imagination, boiling imagination, wild imagination, bold imagination, daring imagination, playful imagination, lively imagination, fertile imagination, fancy, mind's eye, such stuff as dreams are made of, ideality, idealism, romanticism, utopianism, castle-building, dreaming, phrensy, frenzy, ecstasy, extasy, calenture, reverie, trance, day dream, golden dream, somnambulism, conception, Vorstellung, excogitation, a fine frenzy, cloudland, dreamland, flight of fancy, fumes of fancy, thick coming fancies, creation of the brain, coinage of the brain, imagery, conceit, maggot, figment, myth, dream, vision, shadow, chimera, phantasm, phantasy, fantasy, fancy, whim, whimsey, whimsy, vagary, rhapsody, romance, gest, geste, extravaganza, air drawn dagger, bugbear, nightmare, flying Dutchman, great sea serpent, man in the moon, castle in the air, pipe dream, pie-in-the-sky, chateau en Espagne, Utopia, Atlantis, happy valley, millennium, fairyland, land of Prester John, kindgom of Micomicon, work of fiction, Arabian nights, le pot au lait, dream of Alnashar, illusion, phantom, Fata Morgana, vapor, stretch of the imagination, mythogenesis, idealist, romanticist, visionary, mopus, romancer, dreamer, somnambulist, rhapsodist, castle-buildier, fanciful projector, imagined, ben trovato, air drawn, airbuilt, imagining, imaginative, original, inventive, creative, fertile, romantic, high flown, flighty, extravagant, fanatic, enthusiastic, unrealistic, Utopian, Quixotic, ideal, unreal, in the clouds, in nubibus, unsubsantial, illusory, fabulous, legendary, mythical, mythic, mythological, chimerical, imaginary, visionary, notional, fancy, fanciful, fantastic, fantastical, whimsical, fairy, fairy-like, gestic, a change came o'er the spirit of my dream, aegri somnia vana, dolphinum appingit sylvis in fluctibus aprum, fancy light from fancy caught, imagination rules the world, l'imagination gallope, le jugement ne va que le pas, musaeo contingens cuncta lepore, tous songes sont mensonges, Wahrheil und Dichtung, DIVISION II COMMUNICATION OF IDEAS.

phantom circuit, phantom limb, phantom limb pain, phantom limb syndrome, phantom orchid