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]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "cleaning":
   abstergent, abstersion, autoclave, bowdlerization, broom, brush,
   carpet sweeper, catharsis, cathartic, cleansing, comb, currycomb,
   depurative, detergent, detersion, dishcloth, dishwasher, diuretic,
   doormat, dry cleaning, duster, dustpan, emetic, expurgation,
   expurgatory, facecloth, hackle, hairbrush, handkerchief, holystone,
   hose, lustral, lustration, mop, napkin, pumice stone, purgation,
   purgative, purge, purging, purification, purificatory, purifying,
   rake, scraper, scrub brush, scrubber, serviette, sponge,
   steam cleaning, sudarium, swab, toothbrush, toothpick, towel,
   vacuum cleaner, washboard, washer, washing machine, whisk, wisp,
   wringer