WordNet sense 1 (a typeface with thick heavy lines):

boldface

WordNet sense 2 (very steep; having a prominent and almost vertical front):

bluff, sheer

WordNet sense 3 (having a sharp inclination):

steep

WordNet sense 4 (obvious to the eye or mind):

conspicuous

WordNet sense 5 (showing or requiring courage and contempt of danger):

nervy

WordNet sense 6 (having or displaying qualities appropriate for heroes):

heroic

WordNet sense 7 (invulnerable to fear or intimidation):

audacious, brave, dauntless, fearless, intrepid