Confirm (6)
'confirm' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for certify that I've seen before include "Declare; endorse" , "Formally confirm" , "Authorise officially" .)
'confirm' is the definition.
(I know that corroborate is a kind of confirm)
This is the entire clue.
(Other definitions for corroborate that I've seen before include "Confirm - support" , "Back up (a statement)" , "Bear out" , "Confirm (a statement)" .)
'confirm' is the definition.
(to attest to something is to prove or confirm it)
This is the entire clue.
(Other definitions for attest that I've seen before include "Corroborate" , "Adjure" , "University town" , "say, in court" , "Vouch for" .)
'confirm' is the definition.
(I know that verify is a kind of confirm)
This is the entire clue.
(Other definitions for verify that I've seen before include "Prove to be true" , "Ascertain truth or accuracy" , "Demonstrate" , "Check the truth of" , "Check to be true" .)
'confirm' is the definition.
(I know that validate is a kind of confirm)
This is the entire clue.
(Other definitions for validate that I've seen before include "Verify" , "Corroborate" , "Long poem" , "Ratify" , "Confirm or authenticate" .)
'confirm' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aver that I've seen before include "Formally state" , "Declare to be the case" , "Swear" , "State firmly, propound" , "protest" .)