lifespan Get Printable Handwriting Rhymes Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. the period during which something is functional as between birth and death Example Sentence The lifespan of a fox in the wild is around 3 years. Synonyms lifetime; time of life; period of life Antonyms death Hear It! Say It! Write It! lifespan Switch to cursive Start Rhymes Two Syllable Rhymes (1) lifespan Share with your friends: