Dictionary.com
Thesaurus.com
Synonyms

for certain

Idioms  

  1. Also, for sure. Without doubt. For example, I can't tell for certain if this is the right color, or I know for sure that she has a new car. The first term dates from the early 1300s. The variant, dating from the late 1500s, is also used colloquially to express agreement or assert the truth of a statement, as in Mary is really bossy.—That's for sure, or Are you coming to the party?—For sure I am.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Though they are not crimes, NCHIs stay on police records and can be disclosed during enhanced background checks when applying for certain jobs.

From BBC • Mar. 30, 2026

Private credit remains an evolving part of the investment landscape and may offer diversification and income potential for certain investors.

From MarketWatch • Mar. 30, 2026

The researchers also found that intensity played a larger role for certain diseases.

From Science Daily • Mar. 30, 2026

The Kiddie Tax can apply to unearned income for certain children under 24, making it partly taxed at the parents’ rate.

From The Wall Street Journal • Mar. 23, 2026

What he knew for certain was that he had to get back to the surface before his air ran out.

From "Shipwrecked!" by Martin W. Sandler

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.