Behind and Caudal appendage

Behind noun - The part of the body upon which someone sits.

Caudal appendage and behind are semantically related In some cases you can use "Caudal appendage" instead a noun "Behind".

Caudal appendage noun - Tail especially of a mammal posterior to and above the anus.

Behind and caudal appendage are semantically related in part topic. You can use "Behind" instead a noun phrase "Caudal appendage", if it concerns topics such as tail.