definition of terrapin
Terrapin. A terrapin is a turtle living in fresh or brackish water. Terrapin is an Algonquian word for turtle. In the UK red-eared sliders are known as red-eared terrapins.errapin. A terrapin is a turtle living in fresh or brackish water. Terrapin is an Algonquian word for turtle. In the UK red-eared sliders are known as red-eared terrapins.