OVERESTIMATE
overestimate, overestimation, overrating, overreckoning
(noun) a calculation that results in an estimate that is too high
overestimate, overestimation, overvaluation, overappraisal
(noun) an appraisal that is too high
overestimate, overrate
(verb) make too high an estimate of; “He overestimated his own powers”
overvalue, overestimate
(verb) assign too high a value to; “You are overestimating the value of your old car”
Source: WordNet® 3.1
Etymology
Verb
overestimate (third-person singular simple present overestimates, present participle overestimating, simple past and past participle overestimated)
To judge or calculate too highly.
Antonyms
• (to judge too highly): underestimate
Noun
overestimate (plural overestimates)
An estimate that is too high.
Source: Wiktionary
O`ver*es"ti*mate, v. t.
Definition: To estimate too highly; to overvalue.
O`ver*es"ti*mate, n.
Definition: An estimate that is too high; as, an overestimate of the vote.
Source: Webster’s Unabridged Dictionary 1913 Edition