Here's what rhymes with cavilingness.
willingness Words that almost rhyme with cavilingness
siliceous filminess fierceness skittishness piggishness priggishness derisiveness griminess permissiveness spirituous submissiveness spiritless cliquishness jinrickshas jinrikshas certificates precipitous litigants iniquitous vindictiveness explicitness implicitness significance coincidence ubiquitous distinctiveness duplicitous restrictiveness descriptiveness serendipitous insignificance