Definition
Conspirators are persons who have engaged in a conspiracy — that is, two or more individuals who have agreed, expressly or by conduct, to pursue an unlawful objective or to pursue a lawful objective by unlawful means. The term functions as the plural noun identifying the participants in a conspiracy, as distinct from the offense of conspiracy itself.
In modern law, conspirators need not have executed any formal agreement; the combination may be inferred from circumstantial evidence of coordinated conduct. Each conspirator is generally held liable for acts committed by co-conspirators in furtherance of the common scheme, even if a particular act was unilateral or unknown to others at the time.
Common Language
Modern common usage (Wiktionary): Plural of conspirator; persons engaged in a conspiracy.
Historical common usage (Webster's 1913): One who engages in a conspiracy; a plotter.
The gap here is narrow but real. In ordinary usage, "conspirators" carries a broad sense — anyone secretly plotting anything, including political intrigue, surprise parties, or fiction. In law, the term is bounded by formal elements: agreement, unlawful objective or unlawful means, and (in many jurisdictions) an overt act. The everyday connotation of secrecy or plotting is insufficient on its own to constitute the legal category.
Common Confusion
Conspirators (the persons) are frequently conflated with conspiracy (the offense). The distinction matters for research: sources indexed under "conspiracy" address the elements of the crime; sources addressing "conspirators" more often address the status of participants — including liability rules, the scope of the co-conspirator exception to hearsay, and how membership in the conspiracy is established or terminated. A researcher looking for how one person's acts bind another should follow both threads.
Why It Matters in Research
The historical sources treat "conspirators" primarily as a term of status, defined by reference to the Statute of Conspirators, 33 Edw. I, St. 2 (1305), which named specific categories of offenders — particularly those who bound themselves by oath or covenant to falsely indict others or to maintain false pleas. This statutory definition is narrower than modern usage and reflects a procedural concern (abuse of the indictment process) rather than a general theory of criminal combination.
Researchers working in early English common law materials should be alert to this distinction: "conspirators" in pre-nineteenth century sources may refer specifically to this statutory class, not to the broader modern concept. Bouvier collapses the entry entirely into a cross-reference to conspiracy, signaling that by his era the term had become derivative rather than independently defined.
In modern American law, the term's most consequential research context is evidentiary: the co-conspirator exception under Federal Rule of Evidence 801(d)(2)(E) treats statements made by a co-conspirator during and in furtherance of the conspiracy as non-hearsay. Identifying who qualifies as a conspirator — when the conspiracy began, who joined it, and when it ended — controls admissibility. This body of doctrine is largely absent from the historical dictionaries and must be pursued through the evidence rules and case law.
Jurisdictional variation in the elements required to establish conspiracy (particularly whether an overt act is required) directly affects who counts as a conspirator at any given moment in the alleged scheme. Researchers should not assume uniformity across federal and state sources.
Historical Dictionary Support
The four source dictionaries present a consistent but sparse picture. Black's (both editions) and Burrill point to 33 Edw. I, St. 2 as the defining authority and reproduce substantially identical language, suggesting the entry was carried forward without significant independent analysis. Wharton is cited for the extension of the category to "treasonable purposes," adding the political dimension. Bouvier offers nothing beyond a bare cross-reference to conspiracy.
None of the historical sources address the liability rules that now define the term's practical significance — vicarious liability among co-conspirators, the Pinkerton doctrine, or the evidentiary consequences of conspiracy membership. This is an area where the historical dictionaries are genuinely incomplete rather than merely dated, and modern corpus research requires moving past them quickly.
Jurisdictional Note
Federal law and most states require an agreement plus at least one overt act to establish a conspiracy; some federal statutes (notably drug conspiracy under 21 U.S.C. § 846) do not require an overt act. Who qualifies as a conspirator, and from what point, varies accordingly and affects both criminal exposure and evidentiary admissibility.
Encyclopedia Cross-Reference
Co-Conspirator Statements — Rule 801(d)(2)(E) (Law Mind Civil Procedure & Evidence Encyclopedia): Directly addresses the evidentiary consequences of conspirator status, including how courts determine membership in and the scope of the conspiracy for hearsay purposes.