by-product

American  

[bahy-prod-uhkt] / ˈbaɪˌprɒd əkt /

noun

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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Etymology

Origin of by-product

First recorded in 1900–05

Example Sentences

This underused by-product has shown strong potential for enriching bread with protein, fiber, and antioxidant compounds.

From Science Daily • Feb. 8, 2026

“Silver supply is structurally inelastic, with around 70-80% of global silver output coming as a by-product from mines that primarily produce lead, zinc, copper or gold,” Manthey said.

From The Wall Street Journal • Dec. 9, 2025

However, the connections to several remote farms were largely a by-product of the government deciding an electricity supply was needed to three emergency telecommunication masts there.

From BBC • Dec. 8, 2025

“Belief in a novel is, for me, a by-product of a certain kind of sentence,” Smith observes.

From Los Angeles Times • Oct. 28, 2025

It’s a by-product of the famous superstition about splitting an infinitive.

From "Woe Is I" by Patricia T. O'Conner

Related Words

• outgrowth