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

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Etymology

Origin of by-product

First recorded in 1900–05

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Example Sentences

See Examples For:

by-product by-products

At the $25 million transaction price in Capstone shares, Hutchison calculates that Capstone paid less than a cent per pound for the copper resources alone, excluding by-product credits.

From The Wall Street Journal ● Sep. 1, 2026

The by-product is pivoting into its professional era in the 21st century.

From BBC ● Jul. 23, 2026

Instead, they are a by-product of the ear's physiological sound amplification process.

From Science Daily ● Jul. 19, 2026

Lynas however, says its by-product from rare earth refining produces a non-toxic, non-radioactive magnesium-rich gypsum and an iron phosphate with a very low level of naturally occurring radioactive material.

From Barron's ● Apr. 22, 2026

But his anxieties about class and status were so deep that he could not bear the thought that his own “intelligence” might merely be the by-product of privilege and opportunity.

From "The Gene" by Siddhartha Mukherjee

The licence was issued as environmental watchdogs such as Greenpeace raised concerns over the management of radioactive by-products.

From Barron's ● Apr. 22, 2026

The company’s strong performance in by-products such as lead and zinc was driven by strong grades at its Fresnillo mine in Mexico, they say.

From The Wall Street Journal ● Apr. 22, 2026

This metabolism creates toxic by-products called formaldehyde, formate and formic acid.

From BBC ● Nov. 22, 2024

Fear and suspicion are, of course, common by-products of war.

From Los Angeles Times ● Oct. 28, 2024

If this is all that atoms have, then the qualities that we perceive in the world—colour, taste, smell, sound, texture, temperature—must be by-products of size, shape and movement.

From "The Invention of Science" by David Wootton

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