psalterium
Concise Oxford English Dictionary © 2008 Oxford University Press:
psalterium /sɔːlˈtɪərɪəm, sɒl-/
▶noun another term for omasum.
– origin C19: from L., lit. ‘psalter’ (see psalter), because of its many folds of tissue, resembling pages of a book.
'psalterium' also found in these Oxford entries:

