Co Get Printable Handwriting (co) 1 syllables Hear It! Say It! Write It! Learn It! Spelling Test Definition preposition. a prefix meaning together or with. Example Sentence Cobalt is a chemical element with the symbol Co and atomic number 27. More Example Sentences They worked as co authors on the book. Synonyms together; jointly; with Hear It! Say It! Write It! Co Switch to cursive Start Share with your friends: