causticity

noun2

1. •
   The quality of being physically caustic; burning, corrosive.

   • Some years ago, we read in a U.S. trade paper a method for determining causticity of bottle-washing solution when foil labels are contained on the bottles undergoing cleansing treatment. — 1961
2. •
   (figurative) Being caustic in speech, humour etc.

   • […] one in whom a discreet causticity went along with a manner less genial than polite […] — 1924