The Collaborative International Dictionary of English v.0.48:

Curliness \Curl"i*ness\ (k?rl"?-n?s), n.
   State of being curly.
   [1913 Webster]

WordNet (r) 3.0 (2006):

curliness
    n 1: (of hair) a tendency to curl [syn: curliness, waviness]
         [ant: straightness]