due diligence

noun

1
law : the care that a reasonable person exercises to avoid harm to other persons or their property
failed to exercise due diligence in trying to prevent the accident
2
business : research and analysis of a company or organization done in preparation for a business transaction (such as a corporate merger or purchase of securities)

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Doing Your Due Diligence

Due diligence has been used since at least the mid-fifteenth century in the literal sense “requisite effort.” Centuries later, the phrase developed a legal meaning, namely, “the care that a reasonable person takes to avoid harm to other persons or their property”; in this sense, it is synonymous with another legal term, ordinary care. More recently, due diligence has extended its reach into business contexts, signifying the research a company performs before engaging in a financial transaction. This meaning may also apply to individuals: people are often advised to perform their due diligence before buying a house, signing a loan, or making any important purchase.

Examples of due diligence in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
For brands, the solution supports due diligence on existing suppliers, identifying non-compliance and tracking remediation against a Code of Conduct, Worldly said. — Roy Stephen Canivel, Footwear News, 6 Nov. 2026 The public stance remains, as the statement Friday reads, that Hammond remains the site where due diligence is being finalized and is very much a possibility. — Armando Salguero Outkick, FOXNews.com, 6 Nov. 2026 Before committing capital, investors should perform a similar check as part of their due diligence. — Tomas Milar, Forbes.com, 5 Nov. 2026 Asking whether Broward should too is due diligence, not a conspiracy. — Jose Navarro, Sun Sentinel, 5 Nov. 2026 See All Example Sentences for due diligence

Word History

First Known Use

1598, in the meaning defined at sense 1

Time Traveler
The first known use of due diligence was in 1598

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Cite this Entry

“Due diligence.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/due%20diligence. Accessed 9 Nov. 2026.

Legal Definition

due diligence

noun
1
: such diligence as a reasonable person under the same circumstances would use : use of reasonable but not necessarily exhaustive efforts

called also reasonable diligence

Note: Due diligence is used most often in connection with the performance of a professional or fiduciary duty, or with regard to proceeding with a court action. Due care is used more often in connection with general tort actions.

2
a
: the care that a prudent person might be expected to exercise in the examination and evaluation of risks affecting a business transaction
b
: the process of investigation carried on usually by a disinterested third party (as an accounting or law firm) on behalf of a party contemplating a business transaction (as a corporate acquisition or merger, loan of finances, or especially purchase of securities) for the purpose of providing information with which to evaluate the advantages and risks involved
the greatest exposure…for failure to conduct adequate due diligence arises in the context of public offerings of securities—G. M. Lawrence
c
: the defense (as to a lawsuit) that due diligence was conducted
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