1. a rib or riblike anatomical structure
Usage: anatomy
2. the front edge or margin of an insect’s wing
Usage: entomology
3. a ridge or vein on a leaf or other plant part
Usage: botany

Examples

• The doctor examined the patient’s costa for signs of fracture.
• Each costa of the ribcage protects vital organs.
• The butterfly’s costa forms the leading edge of its forewings.
• Entomologists study the costa to identify different insect species.
• The leaf’s costa runs from base to tip.
• Botanists use the costa pattern to classify plant species.