1. Not able to be ascertained; resisting discovery
   - undiscoverable

See also: indeterminable, undeterminable

• catfish
• catgut
• Catha
• Catha edulis
• Catharacta
• Catharacta skua
• Catharanthus
• Catharanthus roseus
• Cathari
• Catharism
• Cathars
• catharsis
• Cathartes
• Cathartes aura
• cathartic
• cathartid
• Cathartidae
• Cathay
• Cathaya
• cathect
• cathectic
• cathedra
• cathedral
• cathemeral
• Cather