1. Corals having calcareous skeletons aggregations of which form reefs and islands
   - madrepore, madriporian coral

Derived forms: stony corals

Type of: coral

Part of: Madreporaria, order Madreporaria

Encyclopedia: Stony coral

• on the coattails
• on the contrary
• on the dot
• on the face of it
• on the fence
• on the fly
• on the go
• on the hook
• on the house
• on the level
• on the line
• on the loose
• on the mend
• on the nail
• on the nose
• on the off chance
• on the offensive
• on the one hand
• on the other hand
• on the QT
• on the qui vive
• on the road
• on the rocks
• on the ropes
• on the run