Round and round they went with their snakes, snakily, with a soft undulating movement at the knees and hips.
Bloated, sagging, and among those firm youthful bodies, those undistorted faces, a strange and terrifying monster of middle-agedness, Linda advanced into the room, coquettishly smiling her broken and discoloured smile, and rolling as she walked, with what was meant to be a voluptuous undulation, her enormous haunches.
There are no more uses of "undulate" in the book.
Show samples from other sources
A sidewinding snake uses less energy to cover the same distance as a laterally undulating snake uses.
The dancers’ arms undulated in unison to add to the ethereal effect.