PERT
Her pert response to the professor’s question made the whole class chuckle.
Fun Fact
“Pert” once meant “clever” in Middle English but evolved to describe liveliness with a hint of sass. A “pert nose” is small and upturned, while a “pert remark” has just enough spunk to be amusing, not offensive.
UN-juh-layt
(verb) To move with a smooth, wave-like motion; to have a wavy form, surface, or appearance.
The tall grass undulated across the hillside in the breeze, rippling like a slow green tide.
From Latin undulatus, meaning “wavy,” derived from undula, a diminutive of unda, meaning “wave.” The Latin root unda is also the ancestor of words like abound, inundate, and redundant — all carrying the original sense of water flowing or overflowing. The word entered English in the early 17th century via scientific and descriptive writing.
Fun Fact
Undulation is one of nature’s most energy-efficient forms of locomotion. Snakes, eels, and even some bacteria move through undulation, using waves along their bodies to propel themselves forward with minimal energy loss. Engineers have studied this motion extensively in the development of soft robotics and underwater drones — some of the most advanced aquatic robots today mimic the undulating motion of rays and eels to navigate environments that rigid-hulled vessels simply cannot handle.