UNK-choo-uhs
(adjective) Excessively flattering or insincerely earnest.
His unctuous compliments felt more like manipulation than kindness.
Fun Fact
Originally used to describe oily or greasy textures, “unctuous” now refers to personalities that are slick in the worst way. Often applied to salespeople, sycophants, or politicians, it suggests a surface-level charm masking self-interest or deceit. If someone seems “too nice,” they might just be unctuous.
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.