The Collaborative International Dictionary of English v.0.48:

Frugality \Fru*gal"i*ty\, n.; pl. Frugalities. [L. frugalitas:
   cf. F. frugalit['e].]
   1. The quality of being frugal; prudent economy; that careful
      management of anything valuable which expends nothing
      unnecessarily, and applies what is used to a profitable
      purpose; thrift; --- opposed to extravagance.
      [1913 Webster]

            Frugality is founded on the principle that all
            riches have
            limits.                               --Burke.
      [1913 Webster]

   2. A sparing use; sparingness; as, frugality of praise.

   Syn: Economy; parsimony. See Economy.
        [1913 Webster]

WordNet (r) 3.0 (2006):

frugality
    n 1: prudence in avoiding waste [syn: frugality, frugalness]

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "frugality":
   abnegation, austerity, austerity program, canniness, care,
   carefulness, chariness, cheeseparing, constraint, denial,
   economic planning, economicalness, economy, economy of assumption,
   economy of means, elegance, false economy, forbearance,
   forehandedness, frugalness, golden mean, good management,
   husbandry, law of parsimony, management, moderateness, moderation,
   nothing in excess, parsimoniousness, parsimony, pinching,
   providence, prudence, prudential administration, renouncement,
   renunciation, restraint, scrimping, self-control, self-denial,
   self-discipline, self-mastery, self-restraint, skimping, soberness,
   sobriety, sophrosyne, sparingness, stinting, temperance,
   temperateness, thrift, thriftiness, tight purse strings,
   unwastefulness