certify

As a verb certify is

to attest to as the truth or meeting a standard.

In transitive terms the difference between certify and authorize

is that certify is to attest to as the truth or meeting a standard while authorize is to permit (something), to sanction or consent to (something).

Aver is a synonym of certify.

As a noun aver

is ice-floe.

As a verb certify is

to attest to as the truth or meeting a standard.

Insist is a related term of certify.

As verbs the difference between insist and certify

is that insist is to hold up a claim emphatically while certify is to attest to as the truth or meeting a standard.

Avouch is a related term of certify.

As verbs the difference between avouch and certify

is that avouch is to declare freely and openly; to assert while certify is to attest to as the truth or meeting a standard.

As a noun avouch

is (obsolete) evidence; declaration.

In transitive terms the difference between certify and justify

is that certify is to attest to as the truth or meeting a standard while justify is to absolve, and declare to be free of blame or sin.

Asseverate is a related term of certify.

As verbs the difference between asseverate and certify

is that asseverate is to declare earnestly, seriously, or positively; to affirm while certify is to attest to as the truth or meeting a standard.

Protest is a related term of certify.

As a noun protest

is protest.

As a verb certify is

to attest to as the truth or meeting a standard.

As verbs the difference between affirm and certify

is that affirm is to agree, verify or concur; to answer positively while certify is to attest to as the truth or meeting a standard.