The Collaborative International Dictionary of English v.0.48:

Indebt \In*debt"\, v. t. [imp. & p. p. Indebted; p. pr. & vb.
   n. Indebting.] [OE. endetten, F. endetter; pref. en- (L.
   in) + F. dette debt. See Debt.]
   To bring into debt; to place under obligation; -- chiefly
   used in the participle indebted.
   [1913 Webster]

         Thy fortune hath indebted thee to none.  --Daniel.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Indebted \In*debt"ed\, a.
   1. Brought into debt; being under obligation; held to payment
      or requital; beholden.
      [1913 Webster]

            By owing, owes not, but still pays, at once
            Indebted and discharged.              --Milton.
      [1913 Webster]

   2. Placed under obligation for something received, for which
      restitution or gratitude is due; as, we are indebted to
      our parents for their care of us in infancy; indebted to
      friends for help and encouragement. --Cowper.
      [1913 Webster]

WordNet (r) 3.0 (2006):

indebted
    adj 1: owing gratitude or recognition to another for help or
           favors etc
    2: under a legal obligation to someone

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "indebted":
   beholden, bound, burdened with debt, deep in debt, duty-bound,
   embarrassed, encumbered, in debt, in difficulties,
   in embarrassed circumstances, in hock, in the hole, in the red,
   insolvent, involved, liable, mortgaged, obligated, obliged, owing,
   plunged in debt, responsible, tied up, unsound