[syn: loosening, laxation]
The Collaborative International Dictionary of English v.0.48:
Loosen \Loos"en\ (l[=oo]s"'n), v. t. [imp. & p. p. Loosened
   (l[=oo]s"'nd); p. pr. & vb. n. Loosening.] [See Loose, v.
   t.]
   1. To make loose; to free from tightness, tension, firmness,
      or fixedness; to make less dense or compact; as, to loosen
      a string, or a knot; to loosen a rock in the earth.
      [1913 Webster]
            After a year's rooting, then shaking doth the tree
            good by loosening of the earth.       --Bacon.
      [1913 Webster]
   2. To free from restraint; to set at liberty..
      [1913 Webster]
            It loosens his hands, and assists his understanding.
                                                  --Dryden.
      [1913 Webster]
   3. To remove costiveness from; to facilitate or increase the
      alvine discharges of. --Bacon.
      [1913 Webster]
WordNet (r) 3.0 (2006):
loosening
    n 1: an occurrence of control or strength weakening; "the
         relaxation of requirements"; "the loosening of his grip";
         "the slackening of the wind" [syn: relaxation,
         loosening, slackening]
    2: the act of making something less tight [syn: loosening,
       laxation] [ant: tightening]
Moby Thesaurus II by Grady Ward, 1.0:
62 Moby Thesaurus words for "loosening":
   abatement, allayment, alleviation, assuagement, blunting, calming,
   carelessness, damping, deadening, demulcent, demulsion, diminution,
   dulcification, dulling, easiness, easing, easygoingness, emollient,
   falling-off, hushing, impotence, imprecision, indifference, laxity,
   laxness, leniency, lessening, letdown, letup, lightening,
   looseness, lulling, mitigation, modulation, mollification,
   mollifying, negligence, overindulgence, overpermissiveness,
   pacification, palliation, permissiveness, quietening, quieting,
   reduction, relaxation, relaxedness, relaxing, remission,
   remissness, slackening, slackness, sloppiness, softening, softness,
   soothing, subduement, subduing, tempering, tranquilization,
   unrestraint, weakness