Definition
Not capable of being understood. In legal contexts, a document, statement, instruction, pleading, or provision is unintelligible when its meaning cannot be ascertained by a reader or tribunal applying ordinary interpretive methods. The term operates across several legal settings:
1. Pleadings and process. A pleading or writ is unintelligible when its allegations are so obscure, garbled, or contradictory that the opposing party cannot reasonably be expected to respond to them. Courts may strike or require amendment of unintelligible pleadings.
2. Contracts and instruments. A contractual clause or deed provision is unintelligible when no reasonable construction can extract a definite meaning from it. Depending on context, courts may void the offending clause, apply a saving construction, or in some cases void the entire instrument.
3. Jury instructions. An instruction is unintelligible when it fails to convey the applicable legal standard in terms a reasonable juror can apply. Appellate courts treat unintelligible jury instructions as potential grounds for reversal where prejudice is shown.
4. Recorded and transcribed evidence. Testimony, recorded statements, or transcripts may be characterized as unintelligible when portions cannot be deciphered, a designation that affects admissibility, weight, and the accuracy of the record on appeal.
Common Language
Modern common usage (Wiktionary): Not intelligible; unable to be understood.
Historical common usage (Webster's 1913): Not intelligible; not capable of being understood or comprehended; not clear.
The common and legal meanings overlap almost entirely in their basic sense. The legal term carries operational consequences that the common usage does not: a finding of unintelligibility in law is not merely a description of confusion but a legal conclusion that triggers specific remedies — dismissal, amendment, reversal, or exclusion — depending on the procedural context. Researchers should resist treating the term as purely descriptive when encountered in judicial opinions.
Common Confusion
UNINTELLIGIBLE vs. AMBIGUOUS. These terms are often used loosely as synonyms but describe distinct conditions. An ambiguous text has two or more competing, discernible meanings; the problem is surplus meaning. An unintelligible text has no discernible meaning at all; the problem is the absence of meaning. The distinction matters for remedies: ambiguity invites construction and extrinsic evidence; unintelligibility may defeat construction entirely. Bouvier's cross-reference to CONSTRUCTION implicitly acknowledges this boundary — construction rules apply where meaning is uncertain, not where meaning is entirely absent.
UNINTELLIGIBLE vs. VAGUE. Vagueness describes imprecision along a spectrum; a vague term has a core meaning but uncertain edges. Unintelligibility is a more absolute condition. Constitutional vagueness doctrine (applicable to statutes and regulations) is analytically distinct from the private-law finding that a contract clause is unintelligible.
Why It Matters in Research
The term appears in historical sources as a near-synonym for "void for uncertainty," and researchers reading older equity opinions or common law pleading cases must be alert to this usage. In 19th-century practice, courts would sometimes declare an entire instrument void on unintelligibility grounds where modern courts would more likely apply a saving construction or sever the defective clause — the doctrinal tolerance for imprecision has shifted.
In appellate records, particularly pre-20th century transcripts, "unintelligible" appears as a transcription notation alongside dashes or brackets. When encountered in an evidentiary record, it indicates a gap in the source document rather than a legal ruling, and researchers cannot assume that the underlying testimony was excluded on that basis.
Jury instruction challenges using this term are a productive search category in appellate databases. Courts vary in how they distinguish an instruction that is merely confusing from one that is legally unintelligible — the latter being the higher threshold required to warrant reversal without a showing of specific prejudice in some jurisdictions.
Researchers working in contract law should connect this term to the related doctrines of uncertainty and indefiniteness, which are treated inconsistently across treatises and jurisdictions. Some authorities use "unintelligible," "uncertain," and "indefinite" interchangeably; others assign each a distinct analytical role.
Historical Dictionary Support
The three source dictionaries converge on a single, spare definition: that which cannot be understood. Black's first edition is fragmentary as preserved ("not be understood. That which can-"), but the second edition and Bouvier supply the complete formulation. None of the historical sources develops the legal consequences of a finding of unintelligibility, and none distinguishes the term from ambiguity or vagueness. This is a notable gap — the historical dictionaries treat unintelligible as self-defining, leaving the doctrinal work to treatises and case law.
Bouvier's cross-reference to CONSTRUCTION is the most analytically useful signal in the historical record. It suggests that 19th-century practice understood unintelligibility as the outer boundary of interpretive authority: where construction could not salvage meaning, the concept of unintelligibility marked the limit of the court's remedial reach through interpretation.
Jurisdictional Note
The procedural consequences of a finding of unintelligibility vary across jurisdictions, particularly for pleadings. Federal practice under the Rules of Civil Procedure generally favors amendment over dismissal where a pleading is unintelligible; some state courts retain older practice of striking unintelligible pleadings outright. For contracts, civilian-influenced jurisdictions may apply different saving-construction principles than common law courts.