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

In this case, an overlooked by-product has been turned into a functional ingredient that enhances bread nutrition while reducing waste.

From Science Daily • Feb. 8, 2026

Dermot O'Brien from the company said the dust was a by-product of its manufacturing process to make kitchen doors.

From BBC • Feb. 1, 2026

“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

The company said the on-year rise in profitability was due to higher zinc in concentrate sales volumes, a rise in base-metal prices, and by-product revenues combined with significantly lower copper smelter processing charges.

From The Wall Street Journal • Oct. 22, 2025

“Let’s take a look, shall we? Poultry by-product meal, soy protein isolate, corn gluten meal, soy flour...”

From "Sir Fig Newton and the Science of Persistence" by Sonja Thomas

Related Words

• outgrowth