by-product
Definition
A secondary or incidental product made during the creation of another primary product.
हिन्दी एक प्राथमिक उत्पाद के निर्माण के दौरान बनाए गए एक द्वितीयक या अप्रत्यक्ष उत्पाद
Example
"Ethanol is a common by-product of sugar fermentation."