Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

483. Underestimation — N. underestimation; depreciation &c

(detraction) 934; pessimism, pessimist; undervaluing &c v.; modesty &c 881. V. underrate, underestimate, undervalue, underreckon†; depreciate; disparage &c (detract) 934; not do justice to; misprize, disprize; ridicule &c 856; slight &c (despise) 930; neglect &c 460; slur over. make light of, make little of, make nothing of, make no account of; belittle; minimize, think nothing of; set no store by, set at naught; shake off as dewdrops from the lion's mane. Adj. depreciating, depreciated &c v.; unvalued, unprized†.