From <span class="searchmatch">unintermitting</span> + -ness. <span class="searchmatch">unintermittingness</span> (uncountable) The quality of being <span class="searchmatch">unintermitting</span>....
From un- + intermittingly. <span class="searchmatch">unintermittingly</span> (not comparable) Without intermissions; uninterruptedly. 1812, Frances Burney, Journals and Letters, Penguin...
for ten years, was rheumatism in the face combined with toothache <span class="searchmatch">unintermittingly</span> “intermittingly”, in Webster’s Revised Unabridged Dictionary, Springfield...