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 V. Results of Reasoning

482. Overestimation.

   NOUN:OVERESTIMATION &c. v.; exaggeration [See Exaggeration]; vanity [See Vanity]; optimism, pessimism.
  much cry and little wool, much ado about nothing; storm in a teacup; fine talking; fine writing, rodomontade, gush [colloq.], hot air [slang].
  EGOISM, egotism, bombast, conceit, swelled head [slang], megalomania.
  EGOIST, egotist, megalomaniac; optimist, booster [U. S.], pessimist; Rodomont, Braggadochio, braggart, boaster, braggadocio, swaggerer; hot-air artist [slang], gas-bag [slang], wind-bag [slang].
   VERB:OVERESTIMATE, overrate, over-value, overprize, overweigh, overreckon, overstrain, overpraise; estimate too highly, attach too much importance to, make mountains of molehills, catch at straws; strain, magnify; exaggerate [See Exaggeration]; set too high a value upon; think -, make- -much, – too much- of; out-reckon.
  have too high an opinion of oneself (vanity) [See Vanity].
  EULOGIZE, panegyrize, optimize, gush [colloq.], gush over [colloq.], boost [U. S.]; puff or puff up [colloq.]; extol, – to the skies; make the -most, – best, – worst- of; make two bites of a cherry.
   ADJECTIVE:overestimated &c. v.; oversensitive (sensibility) [See Sensibility].
  INFLATED, puffed up; grandiose, stilted, pompous, pretentious, megalomaniacal, braggart, bombastic.
  1. All his geese are swans.
  2. Parturiunt montes nascetur ridiculus mus.—Horace