Definition
DEAL functions as both a verb and a noun in legal contexts, carrying distinct meanings in each form.
1. As a verb: To traffic, trade, or transact business. A party who deals in goods or instruments is engaged in buying, selling, or exchanging them as a course of commercial conduct, not merely as an isolated act. The verb carries a sense of regularity or ongoing commercial engagement rather than a single transaction.
2. As a noun (archaic): A moiety, portion, or share of a thing. This usage is largely obsolete in modern legal writing but appears in historical instruments and pleadings, particularly in property and inheritance contexts.
3. As a noun (informal/commercial): An informal term for a transaction, bargain, or agreement, often used in commercial negotiations, regulatory filings, and transactional practice as shorthand for a contract, merger, acquisition, or other structured arrangement. This usage carries no fixed legal definition but is ubiquitous in practice.
The derived term DEALER carries its own legal significance: a dealer is one who buys to sell again — one who makes successive sales a business, not merely one who buys to keep or who makes goods to sell. This distinction has been consequential in statutory interpretation, particularly in commercial licensing, tax, and regulatory contexts.
Common Language
Modern common usage (Wiktionary): To distribute among recipients; to give out in portions; to have dealings or business; to trade; to distribute cards in a game; to inflict damage or a blow; to conduct oneself.
Historical common usage (Webster's 1913): A part or portion; a share; hence, an indefinite quantity, degree, or extent — as in "a deal of time and trouble." Also used as a verb meaning to distribute or transact.
The gap matters in two directions. First, the casual modern noun ("we made a deal") implies an informal or merely oral agreement, whereas legal practice may treat the same word as encompassing fully binding, complex transactional structures. Second, the historical noun meaning — a portion or share — has no counterpart in modern common speech, creating a trap when reading older legal instruments where "deal" refers to a fractional interest in property rather than a transaction.
Recognized Forms
/SUBTYPES
DEALER: One who buys to sell again as a regular course of business. Statutes governing dealers — in securities, firearms, motor vehicles, controlled substances, and commodities — frequently turn on whether a party is acting as a dealer (systematic commercial activity) or a non-dealer (isolated transactions). The distinction is not merely taxonomic; licensing requirements, tax treatment, and liability rules often apply exclusively to dealers.
COURSE OF DEALING: A sequence of previous conduct between parties to a transaction that establishes a common basis for interpreting their current agreement. This is a term of art under the Uniform Commercial Code and related commercial law, and is distinct from both "course of performance" and "usage of trade."
SELF-DEALING: Conduct by a fiduciary — such as a corporate director or trustee — who acts in a transaction where the fiduciary has a personal interest adverse to the interests of the party owed the fiduciary duty. Self-dealing is a recognized category of breach of fiduciary duty.
DEALING AT ARM'S LENGTH: A transaction conducted between unrelated parties acting in their respective self-interests, without one party dominating or controlling the other. Arm's-length dealing is a baseline assumption in many commercial and tax contexts.
Why It Matters in Research
The term is a false friend across centuries. In modern transactional and regulatory practice, "deal" functions as loose commercial shorthand — its meaning must be drawn from context, not from a fixed legal definition. In historical sources, the same word may refer to a fractional share of property, a usage that has entirely dropped from modern legal vocabulary. Researchers reading older deeds, wills, or equity proceedings should not assume "deal" refers to a transaction.
The verb form and the DEALER derivative are where the research stakes are highest. Statutory definitions of "dealer" vary significantly across regulatory regimes — securities law, UCC Article 2, firearms statutes, and state licensing frameworks each define the term independently. A definition operative in one context cannot be imported wholesale into another. Anderson's note that a bank "dealing" may mean buying and selling for gain including sales on commission illustrates how sector-specific glosses accumulate around the same root word.
COURSE OF DEALING as a defined term of art under the UCC is the most frequently researched compound form. Researchers should take care not to conflate it with "course of performance" (conduct under the current contract) or "usage of trade" (industry norms). The three concepts operate together in UCC interpretation but are hierarchically ranked when they conflict.
The SELF-DEALING subtype connects directly to corporate and trust law and generates substantial case law on fiduciary obligation. Researchers approaching board-of-directors or trustee liability questions will encounter this term as a threshold categorization.
Historical Dictionary Support
The historical dictionaries agree on the core verb: to traffic, transact business, trade. Black's (both editions), Bouvier's, and Anderson's are uniform on this point, and the overlap suggests this was the settled legal meaning throughout the nineteenth century. The second edition of Black's adds the statutory gloss from Pennsylvania authority — that a dealer "is not one who buys to keep, or makes to sell, but one who buys to sell again" — which represents a refinement that proved durable and that echoes in modern statutory interpretation.
Bouvier's is the only source to preserve the archaic noun meaning (a moiety or half of a thing), and does so without explanation or cross-reference, suggesting it was already receding from active legal use by the time of publication. This entry would be easy to overlook; researchers who encounter "deal" as a noun in historical property documents should treat Bouvier's note as a prompt to investigate whether a fractional interest is intended.
What the historical dictionaries miss almost entirely: the modern compound forms — course of dealing, self-dealing, arm's-length dealing — that now carry most of the doctrinal weight. These are products of twentieth-century commercial law codification and corporate law development and will not be found in the shelf sources.
Jurisdictional Note
Statutory definitions of "dealer" vary by subject-matter jurisdiction — federal securities law, the UCC as adopted in each state, and state-specific licensing schemes each supply their own operative definitions. Researchers should identify the governing statute before relying on any dictionary definition of dealer, as the commercial common-law meaning may not control.
Encyclopedia Cross-Reference
The Law Mind Contracts & Commercial Law Encyclopedia — "Interpretation — Course of Dealing, Course of Performance, and Usage of Trade"
The Law Mind Business Organizations & Corporate Law Encyclopedia — "Board of Directors — Duty of Loyalty and Self-Dealing Transactions"
The Law Mind Employment & Labor Law Encyclopedia — "The Duty of Good Faith and Fair Dealing in Employment"