WordWeb Online

1. Oblivious of dangers, perils or calmly resolute in facing them
   - unafraid
    
2. Invulnerable to fear or intimidation
   "fearless reporters and photographers";
   - audacious, brave, dauntless, hardy, intrepid, unfearing

See also: bold, brave, courageous, fear, fearfulness, fright, unapprehensive, unblinking, unflinching, unfrightened, unintimidated, unshrinking

Antonym: afraid

Encyclopedia: Fearless, a novel of Sarah Bowan