another product; one thing made incidentally during creation of another thing.
A side result.
another or extra item; anything produced, such as this course of a manufacture, aside from the major product.
a second or additional item; one thing produced, such as this course of a process or make, as well as the principal item or product: as, wood-tar is gotten as a by-product within the destructive distillation of timber for manufacture of wood-vinegar or wood-spirit.
something made during make of another thing
a secondary and quite often unanticipated effect
a product made during manufacture of another thing