The Collaborative International Dictionary of English v.0.48:

Insolvent \In*sol"vent\, a. [Pref. in- not + solvent: cf. OF.
   insolvent.] (Law)
      (a) Not solvent; not having sufficient estate to pay one's
          debts; unable to pay one's debts as they fall due, in
          the ordinary course of trade and business; as, in
          insolvent debtor.
      (b) Not sufficient to pay all the debts of the owner; as,
          an insolvent estate.
      (c) Relating to persons unable to pay their debts.
          [1913 Webster]

   Insolvent law, or Act of insolvency, a law affording
      relief, -- subject to various modifications in different
      States, -- to insolvent debtors, upon their delivering up
      their property for the benefit of their creditors;
      bankruptcy law. See Bankrupt law, under Bankrupt, a.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Insolvent \In*sol"vent\, n. (Law)
   One who is insolvent; as insolvent debtor; -- in England,
   before 1861, especially applied to persons not traders.
   --Bouvier.
   [1913 Webster]

WordNet (r) 3.0 (2006):

insolvent
    adj 1: unable to meet or discharge financial obligations; "an
           insolvent person"; "an insolvent estate" [ant: solvent]
    n 1: someone who has insufficient assets to cover their debts
         [syn: bankrupt, insolvent]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "insolvent":
   bankrupt, broke, broken, busted, destitute, down-and-out, failed,
   failure, fortuneless, homeless, impoverished, in Queer Street,
   in receivership, in the gutter, in the red, indebted,
   insolvent debtor, lame duck, landless, moneyless, on the rocks,
   out of funds, penniless, propertyless, ruined, unsound, wiped out,
   without a sou



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

INSOLVENT. This word has several meanings. It signifies a person whose
estate is not sufficient to pay his debts. Civ. Code of Louisiana, art.
1980.. A person is also said to be insolvent, who is under a present
inability to answer, in the ordinary course of business, the responsibility
which his creditors may enforce, by recourse to legal measures, without
reference to his estate proving sufficient to pay all his debts, when
ultimately wound up. 3 Dowl. & Ryl. Rep. 218; 1 Maule & Selw. 338; 1 Campb.
it. 492, n.; Sugd. Vend. 487, 488. It signifies the situation of a person
who has done some notorious act to divest himself of all his property, as a
general assignment, or an application for relief, under bankrupt or
insolvent laws. 1 Peters' R. 195; 2 Wheat. R. 396; 7 Toull. n. 45; Domat,
liv. 4, t. 5, n. 1 et 2; 2 Bell's Com. 162, 5th ed.
     2. When an insolvent delivers or offers to deliver up all his property
for the benefit of his creditors, he is entitled to be discharged under the
laws of the, several states from all liability to be arrested. Vide 2 Kent,
Com. 321 Ingrah. on Insolv. 9; 9 Mass. R. 431; 16 Mass. R. 53.
     3. The reader will find the provisions made by the national legislature
on this subject, by a reference to the following acts of congress, namely:
Act of March 3, 1797, 1 Story, L. U. S. 465; Act of March 2, 1799; 1 Story,
L. S. 630; Act of March 2, 1831, 4 Sharsw. Cont. of Story, L. U. S. 2236;
Act of June 7, 1834, 4 Sharsw. Cont. of Story, L. U. S. 2358; Act of March
2, 1837, 4 Sharsw. Cont. of Story, L. U. S. 2536. See Bankrupt.