fellness

From fell +‎ -ness.

fellness (uncountable)

1. The state or quality of being fell; awfulness, horror, cruelty.
   • 1590, Edmund Spenser, “Book II, Canto VIII”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC:

     For very felnesse lowd he gan to weepe, / And said, Caytiue, cursse on thy cruell hond [...].