by-products Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. 1 a product made during the manufacture of something else; 2 a secondary and sometimes unexpected consequence Example Sentence Production created two by-products. Spelled with a hyphen. Synonyms spin-off; secondary product; incidental product Antonyms original Hear It! Say It! Write It! by-products Switch to cursive Start Share with your friends: