THESAURUS
Absent
absconded, absentminded, absorbed, abstracted, away, bemused, castle-building, daydreaming, daydreamy, deficient, deleted, departed, disappeared, distrait, dreaming, dreamy, drowsing, ecstatic, elsewhere, engrossed, faraway, forgetful, gone, half-awake, heedless, in a reverie, in the clouds, keep away from, lacking, lost, lost in thought, meditative, missing, mooning, moonraking, museful, musing, napping, no longer present, nodding, nonattendant, nonexistent, not found, not present, oblivious, off, omitted, out, out of sight, pensive, pipe-dreaming, preoccupied, rapt, somewhere else, stargazing, subtracted, taken away, taken up, transported, unconscious, vanished, wanting, withdraw from, woolgathering, wrapped in thought
ROGET THESAURUS
Absent
Inexistence
N
inexistence, nonexistence, nonsubsistence, nonentity, nil, negativeness, nullity, nihility, nihilism, tabula rasa, blank, abeyance, absence, no such thing, nonbeing, nothingness, oblivion, annihilation, extinction, extinguishment, extirpation, Nirvana, obliteration, inexistent, nonexistent, negative, blank, missing, omitted, absent, insubstantial, shadowy, spectral, visionary, unreal, potential, virtual, baseless, in nubibus, unsubstantial, vain, unborn, uncreated, unbegotten, unconceived, unproduced, unmade, perished, annihilated extinct, exhausted, gone, lost, vanished, departed, gone with the wind, defunct, fabulous, ideal, supposititious &c, negatively, virtually, non ens.
Absence
N
absence, inexistence, nonresidence, absenteeism, nonattendance, alibi, emptiness, void, vacuum, vacuity, vacancy, tabula rasa, exemption, hiatus, lipotype, truant, absentee, nobody, nobody present, nobody on earth, not a soul, ame qui vive, absent, not present, away, nonresident, gone, from home, missing, lost, wanting, omitted, nowhere to be found, inexistence, empty, void, vacant, vacuous, untenanted, unoccupied, uninhabited, tenantless, barren, sterile, desert, deserted, devoid, uninhabitable, without, minus, nowhere, elsewhere, neither here nor there, in default of, sans, behind one's back, the bird has flown, non est inventus, absence makes the heart grow fonder, absent in body but present in spirit, absento nemo ne nocuisse velit, Achilles absent was Achilles still, aux absents les os, briller par son absence, conspicuous by his absence, in the hope to meet shortly again and make our abs.
Incogitancy
N
incogitancy, vacancy, inunderstanding, fatuity thoughtlessness, vacuity, couch potato, vegetable, vacant, unintellectual, unideal, unoccupied, unthinking, inconsiderate, thoughtless, mindless, no-brain, vacuous, absent, diverted, irrational narrow-minded, unthought of, undreamt 'of, unconsidered, off one's mind, incogitable, not to be thought of, absence d'esprit, pabulum pictura pascit inani.
Inattention
N
inattention, inconsideration, inconsiderateness, oversight, inadvertence, inadvertency, nonobservance, disregard, supineness, etourderie, want of thought, heedlessness, insouciance, abstraction, absence of mind, absorption of mind, preoccupation, distraction, reverie, brown study, deep musing, fit of abstraction, inattentive, unobservant, unmindful, heedless, unthinking, unheeding, undiscerning, inadvertent, mindless, regardless, respectless, listless, blind, deaf, bird-witted, hand over head, cursory, percursory, giddy-brained, scatter-brained, hare-brained, unreflective, unreflecting, ecervele, offhand, dizzy, muzzy, brainsick, giddy, giddy as a goose, wild, harum-scarum, rantipole, highflying, heedless, careless, inconsiderate, thoughtless, absent, abstracted, distrait, absentminded, lost, lost in thought, wrapped in thought, rapt, in the clouds, bemused, dreaming on other things, musing on other things, preoccupied, engrossed, daydreaming, in a reverie, off one's guard, napping, dreamy, caught napping, disconcerted, distracted, put out, inattentively, inadvertently, absent-mindedly, per incuriam, sub silentio, Int, stand at ease, stand easy!, the attention wanders, one's wits gone a woolgathering, one's wits gone a bird's nesting, it never entered into one's head, the mind running on other things, one's thoughts being elsewhere, had it been a bear it would have bitten you.