1. Uncertain of all claims to knowledge
   - agnostic

See also: agnostic, nescient, unbelieving

• genus Corypha
• genus Coryphantha
• genus Corythosaurus
• genus Coscoroba
• genus Cosmocampus
• genus Cosmos
• genus Costia
• genus Cotinga
• genus Cotinus
• genus Cotoneaster
• genus Cottus
• genus Cotula
• genus Coturnix
• genus Coumarouna
• genus Cracticus
• genus Crambe
• genus Crangon
• genus Craspedia
• genus Crassostrea
• genus Crassula
• genus Crataegus
• genus Crateva
• genus Crax
• genus Crepis
• genus Crescentia