Definition
A nonsuit is a termination of a plaintiff's lawsuit that does not reach a decision on the merits. It operates as a judgment against the plaintiff — not because the defendant prevailed on the substance of the claim, but because the plaintiff failed to prosecute, abandoned the action, or could not survive a threshold evidentiary challenge at trial. The key consequence, and the central research variable, is whether a nonsuit bars the plaintiff from bringing the same claim again.
Two principal forms exist:
(1) Voluntary nonsuit. The plaintiff elects to withdraw the action, typically upon discovering a procedural defect, a weakness in proof, or a timing problem. Historically, a plaintiff could take a voluntary nonsuit as of right at almost any point before verdict; modern practice has significantly curtailed this freedom, often requiring court approval or conditioning withdrawal on the payment of costs.
(2) Involuntary (compulsory) nonsuit. The court dismisses the action against the plaintiff's will — typically because the plaintiff failed to appear, failed to prosecute with required diligence, or, at trial, failed to present evidence legally sufficient to go to the jury. This form is closer in effect to a directed verdict for the defendant, though historically the two were procedurally distinct.
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Common Language
Modern common usage (Wiktionary): "A lawsuit that is dismissed as having been brought without cause, prior to an adjudication on the merits."
Historical common usage (Webster's 1913): "A neglect or failure by the plaintiff to follow up his suit; a stopping of the suit; a renunciation or withdrawal of the cause by the plaintiff, either because he is satisfied that he can not support it, or upon the judge's expressing his opinion."
The ordinary-language definitions are not wrong, but they flatten a distinction that matters enormously in legal research: a nonsuit is not necessarily a finding that the case was without cause. A voluntary nonsuit may involve a perfectly meritorious claim that the plaintiff simply needs to re-file in better form. The common definitions also do not capture the res judicata question — whether the nonsuit forecloses refiling — which is the operative issue in most legal disputes about the term.
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Common Confusion
NONSUIT vs. DISMISSAL (modern practice): In federal court and most modern state courts, the nonsuit as a distinct procedural category has been largely absorbed into voluntary dismissal (Fed. R. Civ. P. 41) and judgment as a matter of law (Fed. R. Civ. P. 50). Many jurisdictions that have adopted rules-based civil procedure have formally abolished "nonsuit" as a term of art, replacing it with these modern equivalents. When researching cases decided after a jurisdiction adopted its rules of civil procedure, a researcher must determine whether "nonsuit" survives as a live term or is used loosely as a synonym for dismissal.
NONSUIT vs. DIRECTED VERDICT: An involuntary nonsuit and a directed verdict can produce identical practical outcomes, but they are not the same thing. A nonsuit historically left open the possibility of re-filing; a verdict on the merits did not. Some courts and older writers used the terms interchangeably, which creates traps in historical case research.
NONSUIT vs. NON PROSEQUITUR (non pros): These terms overlap substantially and some dictionaries treat them as synonyms. Strictly, non prosequitur referred to a judgment entered for failure to take a required procedural step within the allotted time — closer to a default for inaction — while nonsuit was broader and could encompass in-court abandonment. The distinction blurs quickly in historical sources.
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Recognized Forms
/SUBTYPES
Voluntary nonsuit: Plaintiff-initiated withdrawal before verdict. Effect on future litigation varies by jurisdiction and era.
Involuntary (compulsory) nonsuit: Court-ordered termination for failure to appear, failure to prosecute, or insufficient evidence at trial.
Nonsuit for want of prosecution: A species of involuntary nonsuit entered when a plaintiff allows excessive time to pass without advancing the case. Equivalent in effect to modern dismissal for failure to prosecute.
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Why It Matters in Research
Res judicata is the central research issue. The historical common law rule was that a nonsuit — particularly a voluntary one — did not bar refiling because it was not a judgment on the merits. That rule made nonsuit an attractive escape hatch for plaintiffs in trouble. But jurisdictions diverged, courts created exceptions, and modern rules have complicated the picture further. When a historical case turns on whether an earlier nonsuit bars the current action, the researcher must identify (a) the jurisdiction, (b) the date, (c) whether it was voluntary or involuntary, and (d) the applicable rule or statute at the time.
Terminology instability across eras is a serious trap. Pre-rules courts used "nonsuit," "non pros," and sometimes "dismissal" interchangeably. Post-rules courts may use "dismissal" to mean what older courts called "nonsuit," or may retain "nonsuit" as a term of art with a jurisdiction-specific meaning that differs from the historical baseline. A case decided in Pennsylvania state court (which retains "nonsuit" as a formal procedural term) means something different from the same word appearing in a 19th-century English report or a federal court opinion from the 1940s.
Corpus researchers will find nonsuit appearing heavily in procedural law materials, pleading treatises, and appellate opinions addressing the scope of res judicata and collateral estoppel. The term is a reliable signal that you are in pre-merger procedural doctrine territory. When tracking a doctrine forward in time, watch for the shift from "nonsuit" to "voluntary dismissal" or "motion for nonsuit" to "motion for judgment as a matter of law" as jurisdiction-specific markers of procedural modernization.
The nonsuit also appears in equity practice, where its function was somewhat different. Equity courts could nonsuit a plaintiff for failure to prosecute, but the procedural mechanics and consequences did not always mirror those at common law. Researchers moving between law and equity materials in historical sources should not assume the term carries identical weight across those contexts.
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Historical Dictionary Support
The historical dictionaries converge on the core definition — a plaintiff's failure or abandonment, either voluntary or compelled — and all distinguish between the two main forms. Bouvier is the most useful of the shelf sources for capturing the judgment-against-plaintiff framing and the distinction between voluntary abandonment and inability to prove the case. Burrill provides the clearest articulation of the voluntary/compulsory distinction and ties the voluntary form explicitly to the plaintiff's in-court discovery of defect — a historically important feature because it explains why plaintiffs used voluntary nonsuit as a tactical maneuver.
Rapalje & Lawrence offers the Norman-French etymology (nonsue, "he does not prosecute his action") and ties it to Coke, which is useful for researchers working in early English materials. Anderson emphasizes the non prosequitur connection and the "nonpros'd" usage, which helps explain why those terms appear so often as synonyms in older American case law.
What the historical dictionaries collectively understate is the res judicata dimension — they describe the mechanics of nonsuit well but do not fully address the downstream question of whether and when a nonsuit bars future litigation. That question, which was extensively litigated, requires going beyond the dictionary shelf to the treatise literature on pleading and procedure.
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Jurisdictional Note
A number of states — Pennsylvania most prominently — have retained "nonsuit" as a formal procedural term with specific statutory or rule-based content that may differ from both the common law baseline and the federal model. Federal courts follow Rule 41 (voluntary dismissal) and Rule 50 (judgment as a matter of law), and "nonsuit" as such has no formal existence in federal practice. Researchers must identify whether the jurisdiction under study has retained, abolished, or statutorily redefined the term before relying on historical authorities.
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Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Civil Procedure — Dismissal and Voluntary Withdrawal; Res Judicata and Claim Preclusion; Historical Forms of Action and Pleading.
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