Undulate (verb)

To move or fluctuate in a wavelike pattern.

Origin:

From the latin word "undula" which means wave or fluctuate.

Examples:

1. The water undulated in the wind.
2. The snake undulated as it moved.
3. The ribbon undulated in the breeze.
4. The grass undulated in the field.
5. The curtain undulated as the wind blew through the open window.