Did You Know?
"Terrestrial" might be a pretty down-to-earth word, but some of its relatives are out of this world. "Terrestrial" first appeared in English in the 15th century and derives from the Latin root "terra," which means "earth." In the mid-1800s "extra-" was added to "terrestrial," giving us "extraterrestrial," an adjective that can be used to describe things (including science fiction creatures) that come from space. "Terrestrial" shares the "-al" suffix with "celestial," which was first used in the 14th century. Not surprisingly, "celestial" ("of or relating to the sky or visible heavens") traces back to the Latin for sky, "caelum."
*Indicates the sense illustrated in the example sentence.