Source : Webster's Revised Unabridged Dictionary (1913)

Debit \Deb"it\, n. [L. debitum what is due, debt, from debere to
   owe: cf. F. d['e]bit. See {Debt}.]
   A debt; an entry on the debtor (Dr.) side of an account; --
   mostly used adjectively; as, the debit side of an account.

Debit \Deb"it\, v. t. [imp. & p. p. {Debited}; p. pr. & vb. n.
   {Debiting}.]
   1. To charge with debt; -- the opposite of, and correlative
      to, credit; as, to debit a purchaser for the goods sold.

   2. (Bookkeeping) To enter on the debtor (Dr.) side of an
      account; as, to debit the amount of goods sold.

Source : WordNet®

debit
     n : an accounting entry acknowledging sums that are owing [syn:
         {debit entry}] [ant: {credit}]

debit
     v : enter as debit [ant: {credit}]