Definition
In law, an infant is any person who has not yet attained the age of legal majority — historically fixed at twenty-one years, and in most modern jurisdictions reduced to eighteen. The term is entirely age-based and carries no implication about the person's physical or intellectual development. A seventeen-year-old is an infant in law; a newborn and a twenty-year-old are equally infants for legal purposes.
The central legal consequence of infancy is limited contractual capacity. Contracts entered into by an infant are generally voidable at the infant's election — not void outright — meaning the infant may affirm or disaffirm the agreement upon reaching majority. Certain categories of contract, most notably those for necessaries (food, shelter, clothing, medical care, and in some formulations education), are binding on infants to the extent of the reasonable value of the goods or services supplied.
Common Language
Modern common usage (Wiktionary): A very young human being, from birth to somewhere between six months and two years of age; a baby or newborn requiring near-constant care.
Historical common usage (Webster's 1913): A child in the first period of life, beginning at birth; a young babe. Webster's also acknowledged the legal sense directly: "a person who is not of full age . . . a person under the age of twenty-one years; a minor."
The gap matters. In ordinary speech today, calling a sixteen-year-old an "infant" would be understood as either absurd or metaphorical. In legal texts, particularly historical sources, the same word carries no developmental implication whatsoever. Researchers encountering "infant" in equity treatises, real property conveyances, or contract cases must read it as a technical synonym for "minor," not as a reference to a baby or young child.
Common Confusion
INFANT vs. MINOR: The two terms are functionally synonymous in most historical and modern legal usage, both designating a person below the age of majority. "Minor" is the dominant term in modern American statutes and court opinions. "Infant" persists in older equity practice, English common law sources, and some formal pleading contexts. Researchers should treat both as interchangeable when reading historical sources but expect modern codes to use "minor" exclusively.
INFANT vs. CHILD: "Child" is a relational term (parent-child) as well as a developmental one. "Infant" in legal sources is strictly a capacity-and-age designation. The overlap in ordinary language can mislead readers of older texts.
Core Elements
The legal status of infancy turns on three questions that recur across historical and modern sources:
1. Age threshold. The common law fixed majority at twenty-one years. Most U.S. states and many common law jurisdictions have lowered this to eighteen by statute. A handful of contexts (alcohol, certain federal rights) retain higher or apply different thresholds.
2. Voidability, not voidness. An infant's contract is voidable at the infant's option, not automatically void. The infant — not the adult contracting party — holds the right to disaffirm. This asymmetry is a recurring point in both historical dictionaries and modern doctrine.
3. Exceptions for necessaries and other binding obligations. Contracts for necessaries bind the infant for reasonable value (not necessarily the contract price). Historical sources also recognize apprenticeship contracts, contracts for basic education, and in some treatments military enlistment as exceptions. The precise scope varies by jurisdiction and era.
Why It Matters in Research
Age threshold shifts are the primary trap. Any source predating the relevant jurisdiction's majority-reduction statute will use twenty-one as the baseline. When reading nineteenth-century equity opinions, treatises, or conveyancing forms, the researcher must resist importing the modern eighteen-year standard without checking when and whether the jurisdiction changed it.
Equity jurisdiction over infants was substantial and generates significant historical corpus material. Courts of equity exercised a parens patriae jurisdiction over infants' property and persons — approving conveyances, supervising trusts, and reviewing contracts — that produced a large body of chancery practice distinct from common law contract rules. A researcher focused on real property or trust history will encounter "infant" constantly in this procedural context.
Pleading and procedure remnants. Some older forms of action and pleading required explicit acknowledgment of a party's infancy (with the infant appearing by guardian or next friend). These procedural artifacts appear throughout historical records even in matters unrelated to incapacity per se. The presence of "by his next friend" language in a case caption signals infancy without necessarily making infancy the legal issue in dispute.
The voidable-versus-void distinction generates substantial case law. Historical sources are not always precise on this point; some older authorities speak loosely of infant contracts being "void" when the better rule is "voidable." Researchers tracing the evolution of this distinction should read carefully rather than take dictionary shorthand at face value.
Historical Dictionary Support
The historical sources are in strong agreement on the core definition: an infant is a person under twenty-one years, a minor. Black's (both editions), Burrill, Bouvier, and Anderson all lead with the twenty-one-year threshold and cite the same cluster of authorities — Coke on Littleton, Blackstone's Commentaries, and Kent's Commentaries — reflecting the uniform common law inheritance of the concept.
Anderson adds substantive depth that the other dictionaries largely skip, noting that an infant "has a mind, but it is immature, insufficient to justify his assuming a binding obligation," and enumerating the recognized exceptions: apprenticeship, necessaries, teaching contracts, and possible military enlistment. This is the most practically useful historical entry for a researcher working on contractual capacity questions.
Bouvier goes slightly further on the age calculation question — noting the civil computation rule by which a person is considered to reach full age at the first instant of the last day of the twenty-first year — a technical point relevant to disputes about whether a contract was made before or after majority.
What the historical dictionaries collectively underemphasize: the voidable-not-void distinction, the infant's power of ratification upon reaching majority, and the procedural mechanics of how infants appeared in court. Researchers seeking those doctrines will need to move beyond dictionary definitions to equity treatises and procedural manuals.
Jurisdictional Note
The age of majority was reduced from twenty-one to eighteen in most U.S. states following the adoption of the Twenty-Sixth Amendment (1971) and the subsequent wave of state legislative reform in the early 1970s. English law similarly reduced the age of majority to eighteen by the Family Law Reform Act 1969. Research in sources predating these reforms — which encompasses virtually all historical common law materials — will use twenty-one as the baseline.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Capacity and Legal Age
See Law Mind Encyclopedia — Contracts (Minors and Necessaries)
See Law Mind Encyclopedia — Parens Patriae and Equity Jurisdiction