English edit

Etymology edit

treacherous +‎ -ness

Noun edit

treacherousness (uncountable)

  1. Treachery; the characteristic of being treacherous.
    • 1901, Bret Harte, “Under the Eaves”, in Under the Redwoods:
      He had an aggressive treacherousness of eye which his potations had not subdued.

References edit