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

See also: brave, courageous, resolute

• submenu
• submerge
• submerged
• submergence
• submergible
• submerging
• submerse
• submersed
• submersible
• submersible warship
• submersion
• submission
• submissive
• submissively
• submissiveness
• submit
• submittal
• submitter
• submucosa
• submucous
• submultiple
• subnormal
• subnormality
• subocean
• suboceanic