The Collaborative International Dictionary of English v.0.48:

Cleaning \Clean"ing\, n.
   1. The act of making clean.
      [1913 Webster]

   2. The afterbirth of cows, ewes, etc. --Gardner.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Clean \Clean\ (kl[=e]n), v. t. [imp. & p. p. Cleaned
   (kl[=e]nd); p. pr. & vb. n. Cleaning.] [See Clean, a.,
   and cf. Cleanse.]
   To render clean; to free from whatever is foul, offensive, or
   extraneous; to purify; to cleanse.
   [1913 Webster]

   To clean out, to exhaust; to empty; to get away from (one)
      all his money. [Colloq.] --De Quincey.
      [1913 Webster]

WordNet (r) 3.0 (2006):

cleaning
    n 1: the act of making something clean; "he gave his shoes a
         good cleaning" [syn: cleaning, cleansing, cleanup]