light speed Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. the speed at which light travels in a vacuum. Example Sentence Light speed is approximately 186282 miles per second. Spelled as two words. More Example Sentences Nothing goes faster than light speed. Synonyms luminal speed; celerity; fast Antonyms slow; sluggish; crawl Hear It! Say It! Write It! light speed Switch to cursive Start Share with your friends:
