by-product

noun

by-prod·​uct ˈbī-ˌprä-(ˌ)dəkt 

variants or byproduct

plural by-products or byproducts

1

: something produced in a usually industrial or biological process in addition to the principal product

Sulfured molasses is a by-product of sugar refining.

—Wayne Gisslen

Small amounts of amyloid beta are generated as an ordinary metabolic byproduct and are believed to do no harm, but larger amounts seem to be tied to Alzheimer's.

—January W. Payne

Meat by-products are parts other than meat, including organs, blood and bone …

—Amy D. Shojai

Among the most commonly occurring and thoroughly studied chlorination byproducts are trihalomethanes …

—Consumer Reports

2

: a secondary and sometimes unexpected or unintended result

Japan's success as an international exporter of manufactured goods is a by-product of the volatile trade among Japanese cities.

—Jane Jacobs

As investor confidence grows, overspending and overborrowing are typically byproducts of an aging bull market.

—Carolyn Bigda

One of the by-products of the information age is an increasing number of data formats.

—John Was

Synonyms of by-product

• derivation
• derivative
• derivate
• result
• product

Examples of by-product in a Sentence

hydrogen is one by-product of that chemical reaction

Recent Examples on the Web

Israel claimed responsibility for the strikes on the South Pars petrochemical complex in Asaluyeh, a key site for Iran's energy sector, both for production of petroleum by-products and for joint work with Qatar on the world's largest natural gas field. —Lucia I Suarez Sang, CBS News, 7 Apr. 2026

These included an ice-cream parlor, souvenir shops, and homes repurposed into Airbnbs—all by-products of a growing tourism industry on Fogo. —Akash Kapur, Travel + Leisure, 7 Apr. 2026

Not all the tendencies that make chatbots dangerous are glitches; some are by-products of how the systems are built. —Ronan Farrow, New Yorker, 6 Apr. 2026

Doing so on a case-by-case, buyer-by-buyer, product-by-product basis would be highly complicated if not impossible for most companies. —Robert Hormats, Fortune, 6 Apr. 2026

Word History

First Known Use

1849, in the meaning defined at sense 1

Rhymes for by-product

• product

Kids Definition

by-product

noun

by-prod·​uct

ˈbī-ˌpräd-(ˌ)əkt

: a product or result produced in addition to the main product or result