The Collaborative International Dictionary of English v.0.48:

Ledger \Ledg"er\(l[e^]j"[~e]r), n. [Akin to D. legger layer,
   daybook (fr. leggen to lay, liggen to lie), E. ledge, lie.
   See Lie to be prostrate.]
   1. A book in which a summary of accounts is laid up or
      preserved; the final book of record in business
      transactions, in which all debits and credits from the
      journal, etc., are placed under appropriate heads.
      [Written also leger.]
      [1913 Webster]

   2. (Arch.)
      (a) A large flat stone, esp. one laid over a tomb. --Oxf.
          Gloss.
      (b) A horizontal piece of timber secured to the uprights
          and supporting floor timbers, a staircase,
          scaffolding, or the like. It differs from an intertie
          in being intended to carry weight. [Written also
          ligger.]
          [1913 Webster]

   Ledger bait, fishing bait attached to a floating line
      fastened to the bank of a stream, pond, etc. --Walton.
      --J. H. Walsh.

   Ledger blade,a stationary shearing blade in a machine for
      shearing the nap of cloth.

   Ledger line. See Leger line, under 3d Leger, a.

   Ledger wall (Mining), the wall under a vein; the foot wall.
      --Raymond.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ledger
    n 1: a record in which commercial accounts are recorded; "they
         got a subpoena to examine our books" [syn: ledger,
         leger, account book, book of account, book]
    2: an accounting journal as a physical object; "he bought a new
       daybook" [syn: daybook, ledger]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "ledger":
   Domesday Book, account, account book, accounts payable ledger,
   accounts receivable ledger, address book, adversaria, album,
   annual, appointment calendar, appointment schedule, balance sheet,
   bank ledger, bankbook, bill, bill of fare, bill of lading,
   blankbook, blotter, books, calendar, card ledger, carte, cashbook,
   catalog, classified catalog, commonplace book, cost card,
   cost ledger, cost sheet, court calendar, daybook, desk calendar,
   diary, diptych, docket, engagement book, factory ledger, inventory,
   invoice, journal, log, logbook, loose-leaf notebook, manifest,
   memo book, memorandum book, memory book, menu, notebook, pad,
   passbook, petty cashbook, pocket notebook, pocketbook,
   police blotter, purchase ledger, record book, register, registry,
   sales journal, sales ledger, scrapbook, scratch pad,
   spiral notebook, statement, stock ledger, stores ledger,
   suspense ledger, table, tablet, triptych, workbook, writing tablet,
   yearbook



Bouvier's Law Dictionary, Revised 6th Ed (1856):

LEDGER, commerce, accounts, evidence. A book in which are inscribed the
names of all persons dealing with the person who keeps it, and in which
there is a separate account, composed generally of one or more pages for
each. There are two parallel columns, on one of which the party named is the
debtor, and on the other the creditor, and presents a ready means of
ascertaining the state of the account. As this book is a transcript from the
day book or journal, it, is not evidence per se.