Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class IV. Words Relating to the Intellectual Faculties
Division (I) Formation of Ideas
Section II. Precursory Conditions and Operations

458. Inattention.

   NOUN:INATTENTION, inconsideration, want of consideration; inconsiderateness &c. adj.; oversight; inadvertence or inadvertency, nonobservance, disregard.
  supineness (inactivity) [See Inactivity]; étourderie [F.]; want of thought; heedlessness (neglect) [See Neglect]; insouciance (indifference) [See Indifference].
  ABSTRACTION; absence of mind, absorption of mind; preoccupation, distraction, reverie or revery, brown study [colloq.], woolgathering, moonraking [dial. Eng.], pipe dream [colloq.], castle in the air, château en Espagne [F.], fancy, deep musing, fit of abstraction.
   VERB:BE INATTENTIVE &c. adj.; overlook, disregard; pass by (neglect) [See Neglect]; not observe [See Attention]; think little of.
  close -, shut- one’s eyes to; pay no attention to; dismiss -, discard -, discharge- from one’s -thoughts, – mind; drop the subject, think no more of; set -, turn -, put- aside; turn away from, turn one’s attention from, turn a deaf ear to, turn one’s back upon.
  ABSTRACT ONESELF, dream, be somewhere else, be absent, be woolgathering, indulge in reverie or revery.
  ESCAPE NOTICE, escape attention; come in at one ear and go out at the other; forget (have no remembrance) [See Oblivion].
  call off -, draw off -, call away -, divert -, distract- the -attention, – thoughts, – mind; put out of one’s head.
  CONFUSE, disconcert, discompose, put out, perplex, bewilder, moider [dial. Eng.], fluster, flurry, rattle [colloq.], muddle, dazzle.
   ADJECTIVE:INATTENTIVE; unobservant, unmindful, unheeding, undiscerning; inadvertent; mindless, regardless, respectless; listless (indifferent) [See Indifference]; blind, deaf; hen-headed [colloq.], flighty, giddypated, giddy-headed, bird-witted; hand over head [rare]; cursory, percursory [rare], volatile, scatter-brained, harebrained; unreflecting, écervelé [F.], inconsiderate, offhand, thoughtless, dizzy, muzzy [colloq.], brainsick; giddy, – as a goose; wild, harum-scarum [colloq.], rantipole, heedless, careless (neglectful) [See Neglect].
  ABSTRACTED, absent, distrait [F.], woolgathering, moonraking [dial. Eng.], dazed, absent-minded, lost; lost -, wrapped- in thought; rapt, in the clouds, bemused, day-dreaming; dreaming of-, musing on- other things; preoccupied, engrossed (attentive) [See Attention]; in a reverie &c. n.; off one’s guard (inexpectant) [See Inexpectation]; napping; dreamy; caught napping.
  DISCONCERTED, put out &c. v.; rattled [colloq.].
   ADVERB:INATTENTIVELY, inadvertently &c. adj.; per incuriam [L.], sub silentio [L.].
   INTERJECTION:stand at ease, stand easy!    QUOTATIONS:
  1. The attention wanders.
  2. One’s wits gone a -woolgathering, – bird’s nesting.
  3. It never entered into one’s head.
  4. The mind running on other things.
  5. One’s thoughts being elsewhere.
  6. Had it been a bear it would have bitten you.
  7. Aliquando bonus dormitat Homerus.—Horace