Source : Webster's Revised Unabridged Dictionary (1913)

Improperation \Im*prop`er*a"tion\, n. [L. improperare,
   improperatum, to taunt.]
   The act of upbraiding or taunting; a reproach; a taunt.
   [Obs.]

         Improperatios and terms of scurrility.   --Sir T.
                                                  Browne