The Collaborative International Dictionary of English v.0.48:

Assets \As"sets\, n. pl. [OF. asez enough, F. assez, fr. L. ad +
   satis, akin to Gr. ? enough, Goth. saps full. Cf. Assai,
   Satisfy.]
   1. (Law)
      (a) Property of a deceased person, subject by law to the
          payment of his debts and legacies; -- called assets
          because sufficient to render the executor or
          administrator liable to the creditors and legatees, so
          far as such goods or estate may extend. --Story.
          --Blackstone.
      (b) Effects of an insolvent debtor or bankrupt, applicable
          to the payment of debts.
          [1913 Webster]

   2. The entire property of all sorts, belonging to a person, a
      corporation, or an estate; as, the assets of a merchant or
      a trading association; -- opposed to liabilities.
      [1913 Webster]

   Note: In balancing accounts the assets are put on the Cr.
         side and the debts on the Dr. side.
         [1913 Webster]

WordNet (r) 3.0 (2006):

assets
    n 1: anything of material value or usefulness that is owned by a
         person or company