1. Unshaken in purpose
   - undismayed, unshaken 
2. Resolutely courageous
   "undaunted in the face of death"

See also: brave, courageous, resolute

• high-protein diet
• high-ranking
• high-resolution
• high-rise
• high-risk
• high-sounding
• high-speed
• high-speed steel
• high-spirited
• high-spiritedness
• high-stepped
• high-stepping
• high-strength brass
• high-strung
• high-sudsing
• high-tech
• high-tension
• high-ticket
• high-toned
• high-top
• high-topped
• high-up
• high-velocity
• high-vitamin diet
• high-voltage