The Collaborative International Dictionary of English v.0.48:

Nodosity \No*dos"i*ty\, n. [L. nodositas.]
   1. The quality of being knotty or nodose; resemblance to a
      node or swelling; knottiness. --Holland.
      [1913 Webster]

   2. A knot; a node.
      [1913 Webster] Nodosous