The Collaborative International Dictionary of English v.0.48:

Testimonial \Tes`ti*mo"ni*al\, n. [Cf. OF. testimoniale, LL.
   testimonialis, L. testimoniales (sc. litterae). See
   Testimonial, a.]
   1. A writing or certificate which bears testimony in favor of
      one's character, good conduct, ability, etc., or of the
      value of a thing.
      [1913 Webster]

   2. Something, as money or plate, presented to a preson as a
      token of respect, or of obligation for services rendered.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Testimonial \Tes`ti*mo"ni*al\, a. [L. testimonialis: cf. F.
   testimonial.]
   Relating to, or containing, testimony.
   [1913 Webster]

WordNet (r) 3.0 (2006):

testimonial
    adj 1: expressing admiration or appreciation; "testimonial
           dinner"
    2: of or relating to or constituting testimony
    n 1: something that serves as evidence; "his effort was
         testimony to his devotion" [syn: testimony,
         testimonial]
    2: something given or done as an expression of esteem [syn:
       tribute, testimonial]
    3: something that recommends (or expresses commendation of) a
       person or thing as worthy or desirable [syn:
       recommendation, testimonial, good word]

Moby Thesaurus II by Grady Ward, 1.0:

154 Moby Thesaurus words for "testimonial":
   admission, advocacy, advocating, advocation, affidavit,
   affirmation, allegation, anniversaries, appreciation, arch,
   assertion, asseveration, attest, attestation, authority,
   authorization, averment, avouchment, avowal, barrow,
   bill of health, blurb, boundary stone, brass, bust, cairn,
   celebrating, celebration, cenotaph, ceremony, certificate,
   certificate of character, certificate of proficiency,
   certification, character, character reference, column,
   commemoration, commendation, compurgation, confirmation,
   credential, cromlech, cross, cup, cyclolith, declaration,
   deposition, diploma, disclosure, dolmen, dressing ship,
   endorsement, evidence, fanfare, fanfaronade, festivity,
   flourish of trumpets, footstone, grave, gravestone, headstone,
   hoarstone, holiday, indication, inscription, instrument in proof,
   jubilee, legal evidence, letter of introduction, manifestation,
   marker, marking the occasion, mausoleum, megalith, memento,
   memorial, memorial arch, memorial column, memorial statue,
   memorial stone, memorialization, memory, menhir, monolith,
   monument, mound, navicert, necrology, notarized statement, note,
   obelisk, obituary, observance, ovation, patronage, pillar, plaque,
   prize, profession, proof, pyramid, recommend, recommendation,
   reference, rejoicing, religious rites, reliquary, remembrance,
   revel, ribbon, rite, ritual observance, rostral column, salute,
   salvo, shaft, sheepskin, show, shrine, sign, solemn observance,
   solemnization, statement, stela, stone, stupa, sworn evidence,
   sworn statement, sworn testimony, symbol, tablet, testament,
   testamur, testimonial banquet, testimonial dinner, testimonium,
   testimony, ticket, toast, token, tomb, tombstone, tope, tribute,
   triumph, trophy, visa, vise, voucher, warrant, warranty, witness,
   word