Source : Webster's Revised Unabridged Dictionary (1913)

Thriftless \Thrift"less\, a.
   Without thrift; not prudent or prosperous in money affairs.
   -- {Thrift"less*ly}, adv. -- {Thrift"less*ness}, n.

Source : WordNet®

thriftlessness
     n : the trait of wasting resources; "a life characterized by
         thriftlessness and waste"; "the wastefulness of missed
         opportunities" [syn: {waste}, {wastefulness}]