The Collaborative International Dictionary of English v.0.48:

Remembrance \Re*mem"brance\ (-brans), n. [OF. remembrance.]
   [1913 Webster]
   1. The act of remembering; a holding in mind, or bringing to
      mind; recollection.
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            Lest fierce remembrance wake my sudden rage.
                                                  --Milton.
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            Lest the remembrance of his grief should fail.
                                                  --Addison.
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   2. The state of being remembered, or held in mind; memory;
      recollection.
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            This, ever grateful, in remembrance bear. --Pope.
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   3. Something remembered; a person or thing kept in memory.
      --Shak.
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   4. That which serves to keep in or bring to mind; a memorial;
      a token; a memento; a souvenir; a memorandum or note of
      something to be remembered.
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            And on his breast a bloody cross he bore,
            The dear remembrance of his dying Lord. --Spenser.
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            Keep this remembrance for thy Julia's sake. --Shak.
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   5. Something to be remembered; counsel; admoni??on;
      instruction. [Obs.] --Shak.
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   6. Power of remembering; reach of personal knowledge; period
      over which one's memory extends.
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            Thee I have heard relating what was done
            Ere my remembrance.                   --Milton.
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   Syn: Recollection; reminiscence. See Memory.
        [1913 Webster]

WordNet (r) 3.0 (2006):

remembrance
    n 1: the ability to recall past occurrences [syn: remembrance,
         recollection, anamnesis]
    2: a recognition of meritorious service [syn: memorial,
       commemoration, remembrance]

Moby Thesaurus II by Grady Ward, 1.0:

178 Moby Thesaurus words for "remembrance":
   Mnemosyne, affect memory, aide-memoire, anamnesis, anniversaries,
   anterograde memory, arch, atavism, barrow, best love, best regards,
   best wishes, boundary stone, brass, bust, cairn, celebrating,
   celebration, cenotaph, ceremony, collective memory, column,
   commemoration, commitment to memory, compliments, computer memory,
   cromlech, cross, cue, cup, cyclolith, devoirs, disk memory, dolmen,
   dressing ship, drum memory, egards, emotional response, engram,
   exercise of memory, fanfare, fanfaronade, favor, festivity,
   flapper, flashback, flourish of trumpets, footstone, gift,
   good wishes, grave, gravestone, greetings, headstone,
   heroic legend, hindsight, hint, hoarstone, holiday, immortal name,
   immortality, information storage, inscription, jogger, jubilee,
   keepsake, kind regards, kindest regards, kinesthetic memory,
   learning by heart, legend, looking back, love, marker,
   marking the occasion, mausoleum, megalith, memento, memento mori,
   memoir, memorabilia, memorandum, memorial, memorial arch,
   memorial column, memorial statue, memorial stone, memorialization,
   memorials, memories, memorization, memorizing, memory, memory bank,
   memory circuit, memory trace, menhir, mind, mneme, monolith,
   monument, mound, necrology, obelisk, obituary, observance, ovation,
   pillar, plaque, present, prize, prompt, prompter, prompting,
   pyramid, race memory, recall, recalling, recollecting,
   recollection, reconsideration, reexperiencing, reflection, regards,
   rejoicing, relic, religious rites, reliquary, reliving,
   remembering, remembrancer, remembrances, reminder, reminiscence,
   respects, retrospect, retrospection, revel, review, revival,
   ribbon, rite, ritual observance, rostral column, rote, rote memory,
   salute, salvo, screen memory, shaft, shrine, skill,
   solemn observance, solemnization, souvenir, stela, stone, study,
   stupa, tablet, tape memory, testimonial, testimonial banquet,
   testimonial dinner, tickler, toast, token, token of remembrance,
   tomb, tombstone, tope, tribute, triumph, trophy, undying fame,
   verbal response, visual memory, youth