1. Occurring ever half hour

1. Every thirty minutes, every half hour

See also: periodic, periodical

• Corypha utan
• Coryphaena equisetis
• Coryphaena hippurus
• Coryphaenidae
• coryphantha
• corythosaur
• corythosaurus
• coryza
• cos
• cos lettuce
• Cosa Nostra
• coscoroba
• cosec
• cosecant
• coseismal
• coseismic
• coset
• cosh
• cosher
• cosign
• cosignatory
• cosigner
• cosily
• Cosimo de Medici
• Cosimo the Elder