The Collaborative International Dictionary of English v.0.48:

Avowal \A*vow"al\, n.
   An open declaration; frank acknowledgment; as, an avowal of
   such principles. --Hume.
   [1913 Webster]

WordNet (r) 3.0 (2006):

avowal
    n 1: a statement asserting the existence or the truth of
         something [syn: avowal, avouchment, affirmation]

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "avowal":
   acceptance, acknowledgment, admission, affidavit, affirmance,
   affirmation, allegation, allowance, announcement, annunciation,
   appreciation, assertion, asseveration, attest, attestation,
   averment, avouchment, compurgation, concession, conclusion,
   confession, creed, declaration, deposition, dictum, disclosure,
   enunciation, instrument in proof, ipse dixit, legal evidence,
   manifesto, owning, owning up, position, position paper,
   positive declaration, predicate, predication, proclamation,
   profession, pronouncement, proposition, protest, protestation,
   recognition, rite of confession, say, say-so, saying, shrift,
   stance, stand, statement, sworn evidence, sworn statement,
   sworn testimony, testimonial, testimonium, testimony, unbosoming,
   utterance, vouch, witness, word