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 VI. Extension of Thought
2. To the Future

508. Inexpectation.

   NOUN:INEXPECTATION [rare], nonexpectation; unforeseen contingency, the unforeseen; false expectation (disappointment) [See Disappointment]; miscalculation [See Misjudgment].
  SURPRISE, sudden burst, thunderclap, blow, shock; bolt out of the blue; surprisement [rare], astoundment [rare], astonishment, mazement [rare], amazement; wonder [See Wonder]; eye opener.
   VERB:NOT EXPECT [See Expectation]; be taken by surprise; start; miscalculate [See Misjudgment]; not bargain for; come -, fall- upon.
  BE UNEXPECTED &c. adj.; come unawares &c. adv.; turn up, pop [colloq.], drop from the clouds; come -, burst -, flash -, bounce -, steal -, creep- upon one; come -, burst- like a -thunderclap, -thunderbolt; take -, catch- -by surprise, – unawares; catch napping, catch off one’s guard; yach [S. Africa].
  SURPRISE, startle, take aback [colloq.], electrify, stun, stagger, take away one’s breath, throw off one’s guard; pounce upon, spring, spring upon, spring a mine upon; stound [archaic], astound; astonish (strike with wonder) [See Wonder].
   ADJECTIVE:NONEXPECTANT, inexpectant; surprised &c. v.; unwarned, unaware; off one’s guard; inattentive [See Inattention].
  UNEXPECTED, unanticipated, unlooked for, unforeseen, unhoped for; dropped from the clouds; beyond -, contrary to -, against- expectation; out of one’s reckoning; unheard of [See exceptional]; startling; sudden (instantaneous) [See Instantaneity].
   ADVERB:UNEXPECTEDLY, abruptly, plump, pop, à l’improviste [F.], unawares; without -notice, – warning, – saying “by your leave”; like a thief in the night, like a thunderbolt; like a lightning flash; in an unguarded moment; suddenly (instantaneously) [See Instantaneity].
   INTERJECTION:heydey! (wonder) [See Wonder]; do tell! [colloq., U. S.].    QUOTATIONS:
  1. Little did one -think, – expect.
  2. Nobody would ever -suppose, – think, – expect.
  3. Who would have thought?
  4. It beats the Dutch.
  5. It is the unexpected that happens.