What does "by-product" mean?

Something made incidentally during the production of something else.

What is a synonym for "by-product"?

Common synonyms include: aftereffect, afterglow, afterimage, aftermath, aftertaste, byproduct.

noun

noun ·Uncommon ·Advanced level

Noun

1
Something made incidentally during the production of something else.
"It was about this time that the first experiments were made (in Germany) with basic slag, a material which had hitherto been regarded as a worthless by-product of steel manufacture. A year or two later field trials were begun in England, with the final result that basic slag has become recognized as a valuable source of phosphorus for growing crops, and is now in constant demand for application to the soil as a fertilizer."
2
a product made during the manufacture of something else wordnet
3
A consequence, especially a side effect.
"The many Indian restaurants all over Britain are a by-product of the large waves of immigration from the subcontinent."
4
a secondary and sometimes unexpected consequence wordnet

"Happiness is not achieved by the conscious pursuit of happiness; it is generally the by-product of other activities."

From by- + product.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.