occultation(n = noun.event) eclipse - one celestial body obscures another;
is a kind of break, interruption
has parts: egress, emersion, immersion, ingress
has particulars: solar eclipse, lunar eclipse, total eclipse, partial eclipse

1.  The hiding of a heavenly body from sight by the intervention of some other of the heavenly bodies; -- applied especially to eclipses of stars and planets by the moon, and to the eclipses of satellites of planets by their primaries. [1913 Webster]

2.  The state of being occult. [1913 Webster]
"The reappearance of such an author after those long periods of occultation." [1913 Webster]

N  darkness, absence of light, blackness, obscurity, gloom, murk, dusk, Cimmerian darkness, Stygian darkness, Egyptian darkness, night, midnight, dead of night, witching hour of night, witching time of night, blind man's holiday, darkness visible, darkness that can be felt, palpable obscure, Erebus, the jaws of darkness, sablevested night, shade, shadow, umbra, penumbra, sciagraphy, obscuration, occultation, adumbration, obumbration, obtenebration, offuscation, caligation, extinction, eclipse, total eclipse, gathering of the clouds, shading, distribution of shade, chiaroscuro, noctivagation, black body, hohlraum, black hole, dark star, dark matter, cold dark matter, dark, darksome, darkling, obscure, tenebrious, sombrous, pitch dark, pitchy, pitch black, caliginous, black, sunless, lightless &c (sun) (light), somber, dusky, unilluminated &c (illuminate), nocturnal, dingy, lurid, gloomy, murky, murksome, shady, umbrageous, overcast, cloudy, darkened, dark as pitch, dark as a pit, dark as Erebus, benighted, noctivagant, noctivagous, in the dark, in the shade, brief as the lightning in the collied night, eldest Night and Chaos, ancestors of Nature, the blackness of the noonday night, the prayer of Ajax was for light.

N  disappearance, evanescence, eclipse, occultation, departure, exit, vanishing point, dissolving views, disappearing, evanescent, missing, lost, lost to sight, lost to view, gone, Int, vanish!, disappear!, avaunt!, get lost!, get out of here.

N  concealment, hiding, occultation, mystification, seal of secrecy, screen, disguise, masquerade, masked battery, hiding place, cryptography, steganography, freemasonry, stealth, stealthiness, sneakiness, obreption, slyness, latitancy, latitation, seclusion, privacy, secrecy, secretness, incognita, reticence, reserve, mental reserve, reservation, arriere pensee, suppression, evasion, white lie, misprision, silence, suppression of truth, underhand dealing, closeness, secretiveness, mystery, latency, snake in the grass, secret, stowaway, concealed, hidden, secret, recondite, mystic, cabalistic, occult, dark, cryptic, cryptical, private, privy, in petto, auricular, clandestine, close, inviolate, tortuous, behind a screen, undercover, under an eclipse, in ambush, in hiding, in disguise, in a cloud, in a fog, in a mist, in a haze, in a dark corner, in the shade, in the dark, clouded, wrapped in clouds, wrapt in clouds, invisible, buried, underground, perdu, secluded, undisclosed &c, untold, covert, untraceable, mysterious, irrevealable, inviolable, confidential, esoteric, not to be spoken of, unmentionable, obreptitious, furtive, stealthy, feline, skulking, surreptitious, underhand, hole and corner, sly, secretive, evasive, reserved, reticent, uncommunicative, buttoned up, close, close as wax, taciturn, secretly, in secret, in private, in one's sleeve, in holes and corners, in the dark, januis clausis, with closed doors, a huis clos, hugger mugger, a la derobee, under the cloak of, under the rose, under the table, sub rosa, en tapinois, in the background, aside, on the sly, with bated breath, sotto voce, in a whisper, without beat of drum, a la sourdine, behind the veil, beyond mortal ken, beyond the grave, beyond the veil, hid from mortal vision, into the eternal secret, into the realms supersensible, into the supreme mystery, in confidence, in strict confidence, in strictest confidence, confidentially, between ourselves, between you and me, between you and me and the bedpost, entre nous, inter nos, under the seal of secrecy, a couvert, underhand, by stealth, like a thief in the night, stealthily, behind the scenes, behind the curtain, behind one's back, behind a screen, incognito, in camera, it must go no further, it will go no further, don't tell a soul, tell it not in Gath, nobody the wiser, alitur vitium vivitque tegendo, let it be tenable in your silence still, background information, deep background information, deep background, background session, backgrounder, not for attribution.