* Marsupial pouch: This is the most accurate term, especially when talking about the pouch of marsupials like kangaroos and koalas.
* Abdominal fold: This is a more general term that refers to any fold of skin in the abdomen, including pouches.
* Pocket: While not strictly scientific, "pocket" can be used in a casual context to describe the pouch.
Ultimately, the best term to use depends on the specific situation and the audience.