From Wiktionary, the free dictionary
From two-faced + -ness.
two-facedness (uncountable)
- The quality of being two-faced.
2002, Sarah Waters, chapter 4, in Fingersmith, London: Virago, →ISBN, part 1, page 91:A servant says, ‘All for my master,’ and means, ‘All for myself’. It’s the two-facedness of it that I can’t bear.