"Roadkill" is a term used to refer to an animal that has been killed by a vehicle on the road. However, there are also several other words that can be used to describe this type of animal casualty. One such word is "carcass," which is a general term used to refer to the remains of an animal after it has died. Another synonym for "roadkill" is "killdeer," which is a term used to describe a bird that has been killed while flying or walking on the road. Other similar words include "traffic victim," "road casualty," and "road victim." All these words are commonly used to refer to casualties that are a result of vehicle accidents on the road.