The Collaborative International Dictionary of English v.0.48:

Diary \Di"a*ry\ (d[imac]"[.a]*r[y^]), n.; pl. Diaries. [L.
   diarium, fr. dies day. See Deity.]
   A register of daily events or transactions; a daily record; a
   journal; a blank book dated for the record of daily
   memoranda; as, a diary of the weather; a physician's diary.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Diary \Di"a*ry\, a.
   lasting for one day; as, a diary fever. [Obs.] "Diary ague."
   --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

diary
    n 1: a daily written record of (usually personal) experiences
         and observations [syn: diary, journal]
    2: a personal journal (as a physical object)

Moby Thesaurus II by Grady Ward, 1.0:

113 Moby Thesaurus words for "diary":
   Clio, Domesday Book, Muse of history, account book, address book,
   adventures, adversaria, album, annals, annual,
   appointment calendar, appointment schedule, autobiography,
   bimonthly, biographical sketch, biography, biweekly, blankbook,
   blotter, calendar, case history, cashbook, catalog, check sheet,
   chronicle, chronicles, chronology, classified catalog, clock card,
   commonplace book, confessions, court calendar, curriculum vitae,
   daily, date slip, datebook, daybook, desk calendar, diptych,
   docket, engagement book, ephemeris, experiences, fortnightly,
   fortunes, gazette, hagiography, hagiology, historiography, history,
   journal, ledger, legend, life, life and letters, life story, log,
   logbook, loose-leaf notebook, magazine, martyrology, memo book,
   memoir, memoirs, memorabilia, memorandum book, memorial, memorials,
   memory book, monthly, necrology, newsmagazine, notebook, obituary,
   organ, pad, periodical, petty cashbook, photobiography, pictorial,
   pocket notebook, pocketbook, police blotter, profile, quarterly,
   record, register, registry, resume, review, scrapbook, scratch pad,
   serial, slick magazine, spiral notebook, story, table, tablet,
   theory of history, time book, time chart, time scale,
   time schedule, time sheet, time study, timecard, timetable,
   trade magazine, triptych, weekly, workbook, writing tablet,
   yearbook



The Devil's Dictionary (1881-1906):

DIARY, n.  A daily record of that part of one's life, which he can
relate to himself without blushing.

    Hearst kept a diary wherein were writ
    All that he had of wisdom and of wit.
    So the Recording Angel, when Hearst died,
    Erased all entries of his own and cried:
    "I'll judge you by your diary."  Said Hearst:
    "Thank you; 'twill show you I am Saint the First" --
    Straightway producing, jubilant and proud,
    That record from a pocket in his shroud.
    The Angel slowly turned the pages o'er,
    Each stupid line of which he knew before,
    Glooming and gleaming as by turns he hit
    On Shallow sentiment and stolen wit;
    Then gravely closed the book and gave it back.
    "My friend, you've wandered from your proper track:
    You'd never be content this side the tomb --
    For big ideas Heaven has little room,
    And Hell's no latitude for making mirth,"
    He said, and kicked the fellow back to earth.
                                                 "The Mad Philosopher"