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Definitions

corroborate

[kuh-rob-uh-reyt, kuh-rob-er-it] / kəˈrɒb əˌreɪt, kəˈrɒb ər ɪt /
VERB
back up information, story
Synonyms
STRONGEST
authenticate confirm justify substantiate validate verify
STRONG
approve certify document endorse establish okay prove ratify strengthen support sustain
WEAK
bear out check on check out check up declare true double-check give nod rubber-stamp
Antonyms
STRONGEST
disprove invalidate veto
STRONG
contradict deny disagree disapprove discredit oppose refuse reject
WEAK
disallow disclaim refute

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.