photo synthesis Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. the process by which a green plant uses sunlight to change water and carbon dioxide into food for itself Example Sentence The students are learning about photo synthesis. Spelled as two words. Synonyms combine; process; use of sunlight Antonyms separate Hear It! Say It! Write It! photo synthesis Switch to cursive Start Share with your friends: