Definition of abomasum in English:



  • The fourth stomach of a ruminant, which receives food from the omasum and passes it to the small intestine.

    • ‘The abomasum, known as the true stomach, normally lies on the floor of the abdomen, but can become filled with gas and rise to the top of the abdomen and become displaced.’
    • ‘Rennet is derived from the abomasum (fourth stomach) of newly born calves.’
    • ‘This ensures that during suckling milk is channeled directly to the abomasum bypassing wasteful ruminal fermentation.’
    • ‘Small rocks were found in the abomasa of 26 of the 31 caribou whose stomachs were examined.’
    • ‘The usual source is the lining of the fourth stomach (the abomasum or true stomach) of a calf, though other young animals may be used.’


Late 17th century: modern Latin, from ab- ‘away, from’ + omasum (see omasum).