Source : Webster's Revised Unabridged Dictionary (1913)

Daybook \Day"book`\ (d[=a]"b[oo^]k`), n.
   A journal of accounts; a primary record book in which are
   recorded the debts and credits, or accounts of the day, in
   their order, and from which they are transferred to the
   journal.

Source : WordNet®

daybook
     n 1: a ledger in which transactions have been recorded as they
          occurred [syn: {journal}]
     2: an accounting journal as a physical object; "he bought a new
        daybook" [syn: {ledger}]