omasum

noun, plural o·ma·sa [oh-mey-suh] /oʊˈmeɪ sə/,

1. the third stomach of a ruminant, between the reticulum and the abomasum; the manyplies.

noun plural -sa (-sə)

1. another name for psalterium

Plural omasa

1. The third division of the stomach in ruminant animals. It removes excess water from food and further reduces the size of food particles before passing them to the abomasum for digestion by enzymes. See more at ruminant.