WordNet sense 1 (a challenge to do something dangerous or foolhardy):

dare

WordNet sense 2 (the trait of being willing to undertake things that involve risk or danger):

boldness, hardihood, hardiness

WordNet sense 3 (radically new or original):

avant-garde, avant-garde

WordNet sense 4 (being or productive of something fresh and unusual; or being as first made or thought of):

original

WordNet sense 5 (disposed to venture or take risks):

audacious, venturesome, venturous

WordNet sense 6 (willing to undertake or seeking out new and daring enterprises):

adventurous