1. (verb) strengthen or make more firm

• confirm

1. (verb) strengthen or make more firm

• affirm

1. (verb) strengthen or make more firm

• corroborate
• validate
• justify
• warrant
• maintain
• uphold
• reconfirm
• verify

1. (verb) strengthen or make more firm

• check
• confirmation
• substantiation
• verification
• collateral
• confirmative
• confirmatory
• confirming
• corroborative
• corroboratory
• substantiating
• substantiative
• validating
• validatory
• verificatory
• verifying
• confirmation
• reaffirmation
• reassertion