invisibleness

invisible +‎ -ness

invisibleness (uncountable)

1. The state of being invisible; invisibility.
   • 1952, C. S. Lewis, The Voyage of the Dawn Treader:

     "Well, then, to put it in a nutshell," said the Chief Voice, "we've been waiting for ever so long for a nice little girl from foreign parts, like it might be you, Missie—that would go upstairs and go to the magic book and find the spell that takes off the invisibleness, and say it. […] "

• invisibility
• invisible
• invisibly

• “invisibleness”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.