a searching inquiry for ascertaining facts; detailed or careful examination.
Origin: 1400–50;late Middle Englishinvestigacio(u)n < Latininvestīgātiōn- (stem of investīgātiō). See investigate, -ion
Synonyms 1, 2. scrutiny, exploration. 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.
1436, from L. investigationem (nom. investigatio) "a searching into," from investigatus, pp. of investigare, from in- "in" + vestigare "to track, trace," from vestigium "footprint, track" (see vestige). Investigate is c.1510 back-formation.