Definition
In law, a person is "drunk" when intoxication from alcohol has progressed to the point that observable or measurable impairment results — whether to judgment, perception, emotional control, speech, coordination, or the integration of thought and voluntary movement. The legal standard is not mere consumption of alcohol, but demonstrable effect on the person's faculties.
Black's Law Dictionary (2nd Ed.) frames the threshold as twofold: either the passions are visibly excited or the judgment is impaired, or the brain is so affected that one or more cognitive and physical processes — intelligence, sense-perception, judgment, continuity of thought, speech, or coordination of volition with muscular action — are operating below their normal capacity.
The term appears across several distinct legal contexts:
1. Criminal law. Drunkenness may be charged as an offense in itself (public intoxication) or may operate as a partial defense, aggravating factor, or element to be proved in connection with other offenses. Voluntary intoxication historically received little sympathy as a defense; its significance varies by jurisdiction and by whether specific or general intent is at issue.
2. Torts and civil liability. Drunk driving liability and dram shop liability both turn on the fact and degree of intoxication. The evidentiary standard may be behavioral (visible impairment), chemical (blood alcohol concentration), or both.
3. Contractual and testamentary capacity. A person who is drunk at the time of executing a contract or will may lack the mental capacity required for a valid legal act, though the standard is closely related to — but not always identical with — criminal intoxication standards.
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Common Language
Modern common usage (Wiktionary): Intoxicated as a result of excessive alcohol consumption; habitually or frequently in a state of intoxication; colloquially, elated or emboldened.
Historical common usage (Webster's 1913): Intoxicated with or as with strong drink; inebriated; drunken — used predicatively, never attributively. Also, drenched or saturated with liquid.
The legal meaning narrows the common meaning in one critical respect: popular usage treats "drunk" as a spectrum condition, often loosely applied. Legal usage demands a threshold — impairment of a specific faculty or observable excitement of the passions. A person who has consumed alcohol is not legally drunk unless that consumption has produced measurable or visible effect. This gap becomes consequential in criminal defense, administrative proceedings (such as license suspension hearings), and civil negligence cases, where the question is not whether a person drank, but whether they crossed the legal threshold of impairment.
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Common Confusion
DRUNK vs. INTOXICATED: The two terms are used interchangeably in many statutes and judicial opinions, but they carry different connotations in formal analysis. "Intoxicated" is the more precise statutory term in modern legislation, often defined by a specific blood alcohol concentration threshold (commonly 0.08% in U.S. driving statutes) or by a functional impairment standard, or both. "Drunk" is the older, more behaviorally grounded term reflecting observable symptoms. Historical sources, including Black's 2nd Ed., use "drunk" as the primary term; modern research will more frequently encounter "intoxicated" as the operative statutory word.
DRUNK vs. UNDER THE INFLUENCE: "Under the influence" is a distinct statutory formulation, common in driving offenses, that may cover impairment at levels below what would satisfy the common understanding of "drunk." A person can be legally "under the influence" without exhibiting the full constellation of symptoms historically associated with drunkenness.
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Why It Matters in Research
Researchers working in the Law Mind corpus should be alert to several navigational issues with this term.
First, the word "drunk" in older legal sources functions as a behavioral and symptomatic standard. When reading 19th- and early 20th-century cases or statutes, "drunk" is doing the work that modern sources assign to "intoxicated" or "under the influence." The terms are not always interchangeable when precision matters — a case decided under a "drunk" standard may have applied a more demanding or differently framed threshold than a modern "DUI" or "DWI" statute would require.
Second, the per se versus behavioral distinction is crucial for research in drunk driving liability and dram shop cases. Modern statutes frequently establish a chemical threshold (BAC 0.08%) as per se evidence of intoxication, entirely separate from behavioral proof. Historical sources predate this chemical standard and define drunkenness entirely in observable, behavioral terms. Research that crosses the pre-chemical and post-chemical statutory eras must account for this shift in how the legal standard is proved, not just defined.
Third, in contractual capacity and testamentary cases, "drunk" operates on a different axis than in criminal or tort law. The question is not whether the person was criminally impaired or a danger to others, but whether, at the moment of execution, they lacked sufficient understanding to form the requisite intent. Cases in this area often turn on the severity and timing of intoxication in ways that traffic cases do not, and the vocabulary tends to track older behavioral formulations more closely than modern chemical ones.
Fourth, researchers following the dram shop thread into the encyclopedia entry (torts_47) should be aware that third-party liability for serving alcohol to an already-drunk patron depends entirely on the legal definition of "drunk" or "visibly intoxicated" at the time of service — a factual and legal question that has generated substantial litigation over what observable signs are sufficient.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides a careful and useful definition that remains relevant as a baseline behavioral standard. The definition is notable for its specificity: it identifies discrete cognitive and physical processes (intelligence, sense-perception, judgment, continuity of thought, speech, and coordination of volition with muscular action) and clarifies that impairment of any one or more of these — not a total collapse — satisfies the legal definition. This "any faculty" framing is doctrinally significant and often overlooked when practitioners or researchers assume "drunk" requires gross or obvious impairment.
What historical dictionaries do not address is the transformation brought about by chemical testing. Black's 2nd Ed., published at a time before Breathalyzer technology and statutory per se BAC limits, defines drunkenness entirely through visible and behavioral evidence. The modern researcher using this definition as a guide must remember that contemporary statutes have layered a chemical standard on top of, or in some jurisdictions in place of, the behavioral standard that Black's describes.
Historical sources also do not engage with the specific intent / general intent distinction that became central in 20th-century criminal law, where the voluntariness of intoxication and the nature of the offense interact with the "drunk" determination.
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Jurisdictional Note
The behavioral definition in Black's 2nd Ed. is broadly representative of the common law baseline, but modern statutory definitions vary significantly. Most U.S. jurisdictions maintain both a per se chemical standard (typically BAC 0.08% for driving offenses) and a functional impairment standard, either of which may independently establish the legal condition. Some jurisdictions set lower thresholds for commercial drivers or minors. Dram shop statutes frequently use "visibly intoxicated" as the operative phrase, making observable behavioral evidence — rather than chemical measurement — the critical standard for third-party liability.
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Encyclopedia Cross-Reference
torts_47: Motor Vehicle and Transportation Torts — Drunk Driving Liability and Dram Shop Acts (The Law Mind Torts & Personal Injury Encyclopedia)
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