At least 160 English words contain the letters "xu," such as amphioxus, amplexus, asexual, exuberance, exude, exult, exurb, exuvia, fixure, flexure, flexuose and mixup. Other words that use this construction include luxury, nexus, plexus, sexual and taxus.
Amphioxus refers to a small, eel-like marine creature, also known as a lancelet. Amphioxus, which means "both ends pointed" in Greek, consists of very simple parts that make up the entire chordate phylum of animals. A single amphioxus contains more than 100 gill slits, which the creature uses to filter food and oxygen from the water. Scientists discovered as many as 5,000 specimens in one square yard of sand off the coast of Jamaica.
An exurb is a town outside of the suburbs in which at least 20 percent of the residents commute to a large urban area for work. In 2000, as many as 10.8 million Americans lived in exurbs, mainly in the South and Midwest. Cities such as Atlanta, Washington and Louisville, Ky., have several counties with exurbs.
Taxus denotes a genus of yew tree that is primarily used an ornamental plant in landscaping. Several taxus species have flourished since the Triassic and Jurassic periods. Yew trees are all poisonous, and the wood of the yew tree has been made into bows and arrows due to its flexibility and durability.