Source : Webster's Revised Unabridged Dictionary (1913)

Decency \De"cen*cy\, n.; pl. {Decencies}. [L. decentia, fr.
   decens: cf. F. d['e]cence. See {Decent}.]
   1. The quality or state of being decent, suitable, or
      becoming, in words or behavior; propriety of form in
      social intercourse, in actions, or in discourse; proper
      formality; becoming ceremony; seemliness; hence, freedom
      from obscenity or indecorum; modesty.

            Observances of time, place, and of decency in
            general.                              --Burke.

            Immodest words admit of no defense, For want of
            decency is want of sense.             --Roscommon.

   2. That which is proper or becoming.

            The external decencies of worship.    --Atterbury.

            Those thousand decencies, that daily flow From all
            her words and actions.                --Milton.

Source : WordNet®

decency
     n 1: the quality of conforming to standards of propriety and
          morality [ant: {indecency}]
     2: the quality of being polite and respectable