1. Hard to defeat
   "an unbeatable ball team" 
2. Incapable of being overcome or subdued
   - invincible, unvanquishable

See also: unconquerable, unstoppable

• Nubian
• Nubian Desert
• nubile
• nubility
• nucellus
• nucha
• nuchal
• Nucifraga
• Nucifraga caryocatactes
• Nucifraga columbiana
• nuclear
• nuclear cataract
• nuclear chemist
• nuclear chemistry
• nuclear club
• nuclear deterrence
• nuclear energy
• nuclear engineering
• nuclear explosion
• nuclear family
• nuclear fission
• nuclear fuel
• nuclear fusion
• nuclear fusion reaction
• nuclear magnetic resonance