Thinning

thinning
    n 1: the act of diluting something; "the cutting of whiskey with
         water"; "the thinning of paint with turpentine" [syn:
         {cutting}, {thinning}]
    

Thin \Thin\, v. t. [imp. & p. p. {Thinned}; p. pr. & vb. n.
   {Thinning}.] [Cf. AS. ge[thorn]ynnian.]
   To make thin (in any of the senses of the adjective).
   [1913 Webster]
    

65 Moby Thesaurus words for "thinning":
      Sanforizing, abatement, adulteration, atrophy, attenuation,
      attrition, blunting, consumption, contour plowing, cultivating,
      cultivation, culture, cutting, damping, deadening, debilitation,
      devitalization, diluent, dilution, dissolvent, dressing, drying,
      drying up, dulling, effemination, emaceration, emaciation,
      enervation, enfeeblement, etherealization, evisceration,
      exhaustion, extenuation, fallowing, fatigue, furrowing, harrowing,
      hoeing, inanition, languishment, listing, mitigation, parching,
      plowing, preshrinkage, pruning, rarefaction, reduction, relaxation,
      resolutive, resolvent, searing, shrinkage, shrinking, shriveling,
      slackening, softening, solvent, subtilization, tilling, wasting,
      weakening, weeding, withering, working