Definition
The child of one's son or daughter; a descendant in the second degree. In legal usage, grandchild typically denotes a biological or legally adopted child of a person's own child. The term appears most frequently in wills, trusts, intestacy statutes, and tax provisions, where its scope—whether it reaches only immediate grandchildren or extends further down the generational line—can determine who takes under a gift or bequest.
Common Language
Modern common usage (Wiktionary): A child of someone's child.
Historical common usage (Webster's 1913): A son's or daughter's child; a child in the second degree of descent.
The everyday meaning and the legal meaning align closely at their core. The research challenge is not a gap between common and legal usage but a gap within legal usage itself: the term's apparent simplicity conceals a contested question about whether it includes great-grandchildren and later descendants, a question courts and drafters have answered inconsistently across jurisdictions and instruments.
Common Confusion
GRANDCHILD vs. GREAT-GRANDCHILD and ISSUE: Whether "grandchildren" in a will or deed sweeps in great-grandchildren has been litigated repeatedly. Courts have split. Some hold that "grandchildren" is a term of limitation that excludes more remote descendants; others, particularly in older equity decisions, read it expansively. The term "issue" presents a related trap: a bequest to "issue" may include grandchildren even when grandchildren are not named, but the per stirpes or per capita distribution rule that applies can differ sharply from what would apply to an explicit bequest to "grandchildren." Researchers should not assume that these terms are interchangeable or that an answer in one instrument type (will vs. deed) controls another.
Why It Matters in Research
The term looks simple enough to skip. Do not skip it. Three research traps recur:
First, the great-grandchildren problem. Rapalje & Lawrence flags the split directly, citing English equity decisions finding that "grandchildren" does include great-grandchildren alongside New York and other American decisions finding it does not. When reading a historical will case, identify the jurisdiction and the date before assuming the court's construction reflects a general rule.
Second, the per stirpes question. How grandchildren take—whether they step into the shoes of a predeceased parent or take equal shares with all other grandchildren—is not resolved by the word itself. Rapalje cites Toller's Executors for the per stirpes rule, but modern intestacy statutes vary, and some jurisdictions have moved to per capita at each generation schemes that produce different results.
Third, the adopted and non-marital grandchild. Historical sources uniformly assume biological descent through a married child. Modern statutes in most U.S. jurisdictions have extended the term to include adopted grandchildren, and many now include grandchildren born outside of marriage. A historical dictionary entry that says only "the child of one's child" tells you nothing about how a 1960s or 1990s statute or instrument would be read. Researchers working in estate or tax contexts must check the governing statute's definitions section and the instrument's own definitions clause before relying on general dictionary meaning.
In the Law Mind corpus, grandchild appears as a term of art primarily in probate, intestacy, and trust materials, but also in social welfare law (Social Security survivor benefits, pension beneficiary designations) and tax law (generation-skipping transfer tax), where regulatory definitions may diverge from common-law constructions.
Historical Dictionary Support
All three source dictionaries offer the same bare definition: "the child of one's child." Black's first and second editions make no attempt to gloss the term further. Rapalje & Lawrence is the outlier in a useful way—it is the only source that acknowledges the primary interpretive dispute and cites specific authorities on both sides. The citations to 2 Eden 194 and 2 Com. Dig. 655 support the inclusive reading; the citations to 3 Barb. (N.Y.) Ch. 488 and 3 Ves. & B. 59 support the exclusive reading. This is a case where Rapalje & Lawrence earns its place on the shelf precisely because Black's minimalism would mislead a researcher into thinking the term is settled.
What all three sources miss entirely: adopted descendants, non-marital descendants, and the modern statutory context. For any post-1950 research problem, the historical dictionaries are starting points only.
Jurisdictional Note
Intestacy statutes vary in whether they define "grandchild" expressly or leave courts to apply common-law construction. For generation-skipping transfer tax purposes, federal tax law supplies its own definitional framework that may not match state probate law. Researchers should never assume that a state court construction of "grandchildren" in a will governs how the term operates in a federal tax or benefit context.