by-product

American  

[bahy-prod-uhkt] / ˈbaɪˌprɒd əkt /

noun

by-products plural

1. a secondary or incidental product, as in a process of manufacture.

2. the result of another action, often unforeseen or unintended.

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by-product British  

noun

1. a secondary or incidental product of a manufacturing process

2. a side effect

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by-product Scientific  

/ bī′prŏd′əkt /

1. Something produced in the process of making something else. When plants produce carbohydrates by photosynthesis, oxygen is released as a by-product. Asphalt and paraffin are by-products of the process of refining crude oil into gasoline.

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Other Word Forms

Noun Inflected Forms

• by-products
  plural

Etymology

Origin of by-product

First recorded in 1900–05

Example Sentences

A key raw material for many of these plastic goods is ethylene, which is derived from naphtha, an oil by-product.

From Barron's • Jun. 28, 2026

The Fed was moving to counter that slowdown, with any lift to stocks a by-product.

From MarketWatch • Jun. 23, 2026

Through it all, however, West struggled with depression and a sense of self-loathing, and had trouble with intimacy, much of it a by-product of a hardscrabble childhood in West Virginia with a domineering father.

From Los Angeles Times • Apr. 14, 2026

The economics of this war have always been a central factor, not a by-product.

From BBC • Apr. 8, 2026

There were those who said that it was just a horrible accident, an inevitable by-product of the fact that police officers sometimes have to make life-or-death decisions in conditions of uncertainty.

From "Blink" by Malcolm Gladwell

Related Words

• outgrowth