the GNU version of the Collaborative International Dictionary of English
adj. Feeding or subsisting on grass, and the like food; -- said of horses, cattle, and other animals.
The Century Dictionary and Cyclopedia
Feeding or subsisting on grass: said of oxen, sheep, horses, etc.
Word Usage
"I even entertained some idea of putting myself on a vegetable diet, vaguely conceiving that, in becoming a graminivorous animal, I should sacrifice to Dora."