The Collaborative International Dictionary of English v.0.48:

Retrenchment \Re*trench"ment\, n. [Cf. F. retrenchment.]
   1. The act or process of retrenching; as, the retrenchment of
      words in a writing.
      [1913 Webster]

            The retrenchment of my expenses will convince you
            that ? mean to replace your fortune as far as I can.
                                                  --Walpole.
      [1913 Webster]

   2. (Fort.) A work constructed within another, to prolong the
      defense of the position when the enemy has gained
      possession of the outer work; or to protect the defenders
      till they can retreat or obtain terms for a capitulation.
      [1913 Webster]

   Syn: Lessening; curtailment; diminution; reduction;
        abridgment.
        [1913 Webster]

WordNet (r) 3.0 (2006):

retrenchment
    n 1: entrenchment consisting of an additional interior
         fortification to prolong the defense
    2: the reduction of expenditures in order to become financially
       stable [syn: retrenchment, curtailment, downsizing]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "retrenchment":
   abbreviation, abridgment, abstract, apocope, arrest, arrestation,
   attrition, check, cheeseparing, compression, condensation,
   conspectus, constraint, control, cooling, cooling down,
   cooling off, curb, curtailment, cut, cutback, cutting,
   deceleration, decrease, decrement, depletion, depreciation,
   derogation, detraction, diminution, dip, disparagement,
   economization, economizing, elision, ellipsis, epitome, extraction,
   foreshortening, hindrance, impairment, inhibition, injunction,
   interdict, legal restraint, lessening, low growth rate, monopoly,
   precis, prohibition, protection, protectionism, protective tariff,
   pullback, rationing, recap, recapitulation, reduction,
   reduction of expenses, reduction of spending, rein, remission,
   restraint, restraint of trade, retardation, retraction, rollback,
   saving, scraping, scrimping, self-control, shortening, shrinkage,
   skimping, slowdown, slowing down, sparing, summary, summation,
   syncope, synopsis, tariff wall, telescoping, thought control,
   truncation