The Collaborative International Dictionary of English v.0.48:
Adventurousness \Ad*ven"tur*ous*ness\, n. The quality or state of being adventurous; daring; venturesomeness. [1913 Webster]WordNet (r) 3.0 (2006):
adventurousness n 1: the trait of being adventurous [syn: adventurousness, venturesomeness]