swiftest Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition adjective. most quick in movement or action. Example Sentence The cheetah is the swiftest animal on land. More Example Sentences He is the swiftest swimmer in the pool. Synonyms fastest; quickest; speediest Antonyms slowest; laziest; sluggish Hear It! Say It! Write It! swiftest Switch to cursive Start Share with your friends: