Definition
A Latin adverb meaning immediately, forthwith, or without delay. In legal usage, instanter is a directional word appearing in court orders and procedural rules commanding a party or officer to act at once—most commonly to plead, produce, or comply on the same day the order is issued, or within twenty-four hours.
The term carries a practical rather than literal meaning. Though derived from a Latin root implying instantaneous action, courts and commentators have long understood instanter to mean within twenty-four hours, not within moments. Some courts have codified this interpretation by express rule.
Historically, the phrase "trial instanter" referred to a specific procedural event: where a prisoner under attainder, and facing execution, pleaded that he was not the same person who had been attainted, the court would conduct the trial on that plea at once, without adjournment.
Common Language
Modern common usage (Wiktionary): immediately; instantly; without delay.
Historical common usage (Webster's 1913): immediately; instantly; at once.
The common and legal meanings appear aligned on the surface, but the gap lies in degree. Common usage implies genuine immediacy—this moment, right now. Legal usage tolerates a practical softening: courts have routinely held that instanter means the same day or within twenty-four hours, not within the instant. A researcher reading an order commanding a party to plead instanter should not assume the common-language sense; the operative meaning depends on the court's rules and the period of the source.
Common Confusion
INSTANTER vs. FORTHWITH vs. IMMEDIATELY: These three terms appear interchangeably in historical sources but are not always synonymous in practice. Forthwith has generally been treated as requiring prompt action within a reasonable time under the circumstances, making it slightly more flexible than instanter. Immediately is the ordinary-English equivalent and is often used in modern drafting to replace both Latin terms, though it carries similar ambiguity. Rapalje & Lawrence cross-references instanter directly to forthwith. Researchers working across periods should not assume these terms were applied uniformly—the operative meaning in any given source depends on the court, the rule, and the era.
Why It Matters in Research
Instanter is a procedural term of art that appears across centuries of court records, orders, rules, and pleading practice. Several research traps deserve attention.
The twenty-four-hour convention is not universal. Burrill notes it as a general usage but acknowledges it is "sometimes so defined by express rule of court"—implying it was not always defined that way. In older English practice, instanter in a rule of court may have meant literally the same day. In American practice, the meaning varied by jurisdiction and era. A researcher dating a procedural dispute should verify whether the applicable court had a local rule fixing the meaning.
The "trial instanter" usage is historically specific. It arose in the context of attainder proceedings—a body of law that has no modern American counterpart. Sources that use this phrase are almost certainly pre-nineteenth century English sources or discussions of English criminal procedure. Do not expect this usage in American materials.
The term largely disappeared from American practice as courts modernized their procedural rules and adopted plain-English drafting standards. Its appearance in a source is itself a dating signal: instanter in an American pleading or order suggests pre-Federal Rules practice (pre-1938 at the federal level) or a jurisdiction that retained older procedural forms. Post-1938 American sources using instanter are likely quoting historical materials or operating under a state code that preserved the term.
Corpus researchers will encounter instanter most densely in: rules of court, pleading practice manuals, attainder and criminal procedure materials, and older equity practice.
Historical Dictionary Support
The five source dictionaries agree on the core definition—immediately, forthwith, without delay—and all converge on the twenty-four-hour practical interpretation. There is no meaningful disagreement among them on the basic meaning.
Burrill is the most analytically careful of the five. His entry makes the important distinction that instanter "does not import an absolutely instantaneous succession, but only that which is comparatively so"—a useful formulation for researchers trying to understand how courts applied the term in practice. This is also the only entry to flag that the twenty-four-hour meaning was sometimes imposed by express rule rather than inherent definition, which is a meaningful observation about interpretive variability.
Black's (both editions) and Rapalje & Lawrence each preserve the "trial instanter" usage in the context of the plea of identity between attainder and execution. This is a genuinely archaic procedural context, and its presence in American legal dictionaries published well into the twentieth century reflects the dictionaries' heavy reliance on English sources rather than any live American practice.
Anderson's entry is the thinnest, offering only the Latin origin and the twenty-four-hour gloss with a cross-reference to "immediately." It adds nothing beyond confirmation.
What the historical dictionaries do not address: the gradual obsolescence of the term in American practice, the relationship between instanter and the Federal Rules of Civil Procedure's displacement of older procedural vocabulary, or any variation in meaning across American state jurisdictions. Researchers should not treat the historical entries as evidence that instanter remained a living term in twentieth-century American courts.
Jurisdictional Note
Instanter was primarily an English common law and early American procedural term. As American jurisdictions adopted reformed procedural codes in the nineteenth and twentieth centuries, the term was largely displaced by forthwith, immediately, or specific time periods. English legal usage retained the term longer. Researchers working with state materials should check whether the relevant jurisdiction had a local rule or statute defining instanter before treating the twenty-four-hour convention as controlling.