Dictionary.com
Thesaurus.com
Synonyms

investigation

American  
[in-ves-ti-gey-shuhn] / ɪnˌvɛs tɪˈgeɪ ʃən /

noun

  1. the act or process of investigating or the condition of being investigated.

    Synonyms:
    exploration, scrutiny
  2. a searching inquiry for ascertaining facts; detailed or careful examination.

    Synonyms:
    exploration, scrutiny

investigation British  
/ ɪnˌvɛstɪˈɡeɪʃən /

noun

  1. the act or process of investigating; a careful search or examination in order to discover facts, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does investigation mean? An investigation is a thorough search for facts, especially those that are hidden or need to be sorted out in a complex situation. The goal of an investigation is usually to determine how or why something happened.Investigations are usually formal and official. The word is commonly associated with police investigations of criminal activity, but it is used in many other contexts to refer to the process of investigating—systematically finding and examining evidence.Example: After a six-month investigation, this news organization uncovered widespread corruption.

Related Words

Investigation, examination, inquiry, research express the idea of an active effort to find out something. An investigation is a systematic, minute, and thorough attempt to learn the facts about something complex or hidden; it is often formal and official: an investigation of a bank failure. An examination is an orderly attempt to obtain information about or to make a test of something, often something presented for observation: a physical examination. An inquiry is an investigation made by asking questions rather than by inspection, or by study of available evidence: an inquiry into a proposed bond issue. Research is careful and sustained investigation.

Other Word Forms

  • investigational adjective
  • preinvestigation noun
  • reinvestigation noun

Etymology

Origin of investigation

First recorded in 1400–50; late Middle English investigacio(u)n from Latin investīgātiōn- (stem of investīgātiō ). See investigate, -ion

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.

Brundage had been following the attacks, too—and, in between classes, was conducting his own investigation.

From The Wall Street Journal • Apr. 3, 2026

“Our investigation revealed that Davis was heavily involved in the decision making process surrounding the allocations of these funds from the very beginning”

From Los Angeles Times • Apr. 2, 2026

Bush was the only person charged in relation to the Legacy investigation.

From BBC • Apr. 2, 2026

Swalwell has denied any wrongdoing in the matter, and a release of records from that investigation now would be unusual.

From Los Angeles Times • Apr. 2, 2026

In the investigation, all the details of that day came out.

From "The Mona Lisa Vanishes" by Nicholas Day