Definition
Second cousins are persons who share a common great-grandparent but do not share a common grandparent. Each person is the grandchild of a sibling of the other person's grandparent. Put differently: if two people are first cousins, their children are second cousins to one another.
The relationship is two generational steps removed from the common ancestor on each side, distinguishing second cousins from first cousins (who share a grandparent) and from first cousins once removed (who are first cousins at different generational levels).
In legal contexts, the term appears most frequently in:
1. Wills and succession law, where class gifts to "cousins" or specific bequests require courts to determine whether second cousins fall within the intended class.
2. Consanguinity statutes, which govern prohibited degrees of relationship for marriage.
3. Next-of-kin and intestacy frameworks, where degree of kinship determines inheritance priority.
Common Language
Modern common usage (Wiktionary): Plural of second cousin — persons sharing the same great-grandparent but not the same grandparent.
Historical common usage (Webster's 1913): Webster's 1913 does not appear to have defined "second cousin" as a distinct entry, but the term was used in general English to describe the child of one's parent's first cousin.
The common and legal definitions are largely consistent, but the legal stakes of the distinction are high in ways ordinary usage does not signal. In everyday speech, "cousin" is often used loosely for any extended family relation. In legal instruments — particularly older wills — courts must determine whether a testator's use of "cousins," "relations," or "next of kin" was intended to include second cousins or was limited to first cousins. The answer can alter inheritance entirely.
Common Confusion
Second cousins are frequently confused with first cousins once removed. A first cousin once removed is the child of your first cousin (or, equivalently, your parent's first cousin). A second cousin is the grandchild of your grandparent's sibling. The two relationships involve the same generational distance in some configurations but different degrees of consanguinity. Legal instruments and statutes that rely on precise kinship language treat these as distinct, and researchers should not assume older documents used the terms with modern precision.
Why It Matters in Research
The primary research significance of "second cousins" lies in three areas:
Wills and class gifts. Courts construing testamentary gifts to "cousins" or "relatives" must determine whether second cousins were intended beneficiaries. Older English and American decisions drew sharp lines. The citation shared by both Black's and Bouvier's — L.R. 19 Ch. Div. 204 — reflects this litigation pattern in Chancery, where disputes over whether second cousins qualified as "next of kin" under a will were common. Researchers working with 19th-century estate disputes should expect to find second-cousin status contested as a threshold question.
Consanguinity and marriage law. Many jurisdictions historically prohibited marriage within certain degrees of kinship. Whether second cousins fell within a prohibited degree varied by jurisdiction and era. Researchers analyzing historical marriage restrictions should not assume that a statute barring marriage between "cousins" included second cousins without checking the governing consanguinity table, which was often appended to the statute or supplied by common law.
Intestacy and next-of-kin priority. Most modern intestacy statutes do not reach second cousins — the estate escheats to the state long before second-cousin heirs are recognized. But in cases of unusual family structures or the absence of closer heirs, second-cousin claims have been litigated. Researchers tracing intestate succession chains in historical records should verify the applicable statute's degree limits.
A terminological trap in historical sources: older legal dictionaries and court opinions sometimes used "cousin" to mean first cousin specifically, "second cousin" in the modern sense, or in some Continental-influenced jurisdictions, "cousin-german" (first cousin) as distinct from "second cousin." Do not import modern precision into historical documents without checking the definitional context.
Historical Dictionary Support
Black's Law Dictionary and Bouvier's Law Dictionary give materially identical definitions: second cousins are persons descended from the same great-grandfather or great-grandmother. Both cite L.R. 19 Ch. Div. 204 as authority, indicating the definition tracks English Chancery practice rather than American statutory codification. This convergence is unsurprising — both dictionaries drew heavily on English common law for family relationship terminology.
Neither dictionary elaborates on how the term operates within intestacy frameworks or consanguinity tables, treating the definition as purely genealogical. This is a meaningful gap: the legal significance of second-cousin status is almost never the label itself but what legal consequence attaches to it in a given doctrinal context. Researchers should treat the dictionary definitions as establishing the genealogical baseline and then consult jurisdiction-specific statutes and case law for the operative legal weight.
Jurisdictional Note
Whether second cousins may legally marry varies by jurisdiction. A small number of U.S. states that restrict first-cousin marriages are silent or permissive as to second cousins; most states do not prohibit second-cousin marriage. Internationally, variation is significant. For intestacy purposes, most modern American statutes cut off inheritance at degrees closer than second cousins, though this too varies by state and by the presence of closer heirs.