Marsupium is the Latin word for a (brood) pouch in several animal groups:
Pouch (marsupial), in marsupials Brood pouch (Peracarida), in peracarid crustaceans Brood pouch (Syngnathidae), in syngnathids such as sea horses Brood pouch (gastropod), a part of the reproductive system of gastropods, a structure in ovoviviparous gastropods, where embryos develop
See also Brood (disambiguation) Pouch (disambiguation)