Definition
In legal contexts, "hair" refers to the capillary filaments growing from the skin of humans or animals. The term arises primarily in two practical settings: (1) as a subject of commercial regulation and statutory interpretation, where its precise boundaries matter for tariff classification, trade definitions, and licensing schemes; and (2) as physical evidence in criminal proceedings, where hair samples may be collected, analyzed, and introduced to establish identity or presence.
The legal definition has been applied narrowly in interpretive disputes. Courts have held that "hair" does not extend to bristles — the coarser, stiffer outgrowths found on certain animals such as swine — distinguishing hair from bristles for purposes of trade and commercial classification.
Common Language
Modern common usage (Wiktionary): A pigmented filament of keratin which grows from a follicle on the skin of humans and other mammals; also, the mass of such growths forming a covering for the body or head.
Historical common usage (Webster's 1913): The collection or mass of filaments growing from the skin of an animal, and forming a covering for a part of the head or for any part or the whole of the body; one of the above-mentioned filaments, consisting of a long, tubular part which is free and flexible, and a bulbous root embedded in the skin.
The gap between common and legal usage is narrow but precise: in ordinary English, "hair" often extends loosely to any similar filamentous outgrowth, including bristles. Legal and judicial usage, particularly in trade and regulatory contexts, imposes a harder line — bristles are categorically excluded, a distinction that carries no weight in everyday speech but material consequences in statutory construction and commercial classification.
Common Confusion
Hair vs. bristles: In regulatory and tariff law, the distinction between "hair" and "bristles" is a formal one, not merely a matter of degree. Bristles — typically sourced from hogs or similar animals — are stiffer, coarser, and have been treated as a separate commercial and legal category. Researchers encountering older trade statutes, tariff schedules, or licensing ordinances should not assume that "hair" in a statutory text encompasses bristles, or vice versa. The case noted in Bouvier (13 Blatch. 251) established this exclusion in a federal context.
Why It Matters in Research
Researchers working in the Law Mind corpus will encounter "hair" in at least three distinct settings, each requiring different attention:
First, in historical trade and tariff materials, the hair/bristle distinction was economically significant. Bristles were a major import commodity used in brush manufacturing, and they were separately classified from animal hair in tariff schedules. A researcher interpreting an old ordinance or customs dispute involving "hair" must check whether the drafters intended the narrow technical meaning excluding bristles, or a broader colloquial one.
Second, Anderson's entry cross-references "hair clippers" under CUTLERY, signaling that licensing and commercial regulation of hair-related trades (barbering, clipping implements) may appear in cutlery statutes and ordinances rather than under a dedicated regulatory framework. Researchers tracing the history of barbering regulation or tool classification should follow that cross-reference.
Third, in modern criminal law, hair evidence carries a different set of research concerns entirely — chain of custody, forensic reliability, and the evolution of microscopic hair analysis (which has been substantially discredited in favor of DNA analysis). This body of law is largely absent from the historical dictionaries and must be researched through case law and forensic science literature directly.
Historical Dictionary Support
Both Anderson's and Bouvier's converge on the core legal proposition: "hair" does not include bristles. Bouvier grounds this in federal case law (13 Blatch. 251), while Anderson's states the rule directly without citation but reaches the same conclusion. The brevity of both entries reflects that "hair" was not a term of elaborate legal art — it arose primarily when statutory or contractual language required a boundary to be drawn.
Neither dictionary addresses hair as physical or forensic evidence, which is unsurprising given their periods. The entire modern body of law surrounding hair evidence in criminal proceedings — including the FBI's decades-long use and subsequent disavowal of microscopic hair comparison testimony — falls entirely outside their scope. Researchers should treat the historical dictionaries as useful only for the trade-classification dimension of this term.