the GNU version of the Collaborative International Dictionary of English
adj. Undulating; undulatory.
The Century Dictionary and Cyclopedia
Undulating; rising and falling in waves or like waves.
Word Usage
"He leaned almost on the neck of the mare, which, as I knew, must close the wound; and the light of his eyes was quite different, and the pain of his forehead unstrung itself, as if he felt the undulous readiness of her volatile paces under him."