Synonyms for Affirmation:

n.

admiration, praise, a pat on the back, brownie points, compliment, acclaim, recognition, regard, credit. allegation, announcement, affirm, apology, apologia, accusation. law. affirmation (noun)
corroboration, acknowledgment, warranty, verification, assurance, avowal, declaration, pledge, certification, proclamation, pronouncement, admission, validation, statement, promise, attestation, assertion, testimony, avouchment, oath.
agreement (noun)
assent.
approval (noun)
permission, acceptance, ratification, Underwriting, approval, endorsement, confirmation, authentication, consent, sanction, assent, approbation.
authorization (noun)
entitlement, blessing, license, warrant, authorization, commission, notarization, designation, enfranchisement, empowerment.
certificate (noun)
certification.
communication (noun)
avowal, assertion, avouchment, statement.
compliance (noun)
fulfillment, submission, adherence, concurrence, conformance, meekness, servility, obedience, resignation, compliance, observance, agreement, respect, conformity, willingness, acquiescence, surrender, deference, submissiveness, obeisance, homage, capitulation, genuflection, fealty.
declaration of the truth of something (noun)
pronouncement, assertion, ratification, testimony, avouchment, oath, confirmation, certification, declaration, statement, avowal, attestation.
guarantee (noun)
guarantee, countersignature, lien, bond, safeguard, collateral, contract, word, token, security, insurance.
pretext (noun)
pretense, claim, smoke screen, plea, alibi, white lie, red herring, rationale, stratagem, loop-hole, pretext, reason, justification, excuse.
promise (noun)
oath.
word (noun)
word.

Other synonyms:

apologia, accusation, announcement, apology. assertion
allegation.

Usage examples for affirmation

  1. Merely the affirmation of ancient privileges. – Patsy by S. R. Crockett
  2. But I shall hope to show you that the true understanding of the context, as well as of the words I have taken for my text, requires the exhortation and not the affirmation – Expositions of Holy Scripture: Romans Corinthians (To II Corinthians, Chap. V) by Alexander Maclaren
  3. And again, if a whole phrase or sentence is made the subject of a finite verb, or of an affirmation no one word contained in it, can singly claim this title. – The Grammar of English Grammars by Goold Brown