What does unilineal mean?
Unilineal describes a system of descent or inheritance that follows a single line of ancestors. In anthropology and genealogy, it can mean tracing relationships through one parental line, such as the male line, rather than through both parents, as in a bilineal system. The word also appears in discussions of inheritance and family property. It is more precise than linear, because a family tree is naturally branching: unilineal specifically identifies the practice or principle of following one ancestral path. The term is formal and relatively uncommon outside specialized writing, but it is useful when distinguishing single-line descent from forms of descent that recognize both parental lines. Its meaning is also distinct from the broader word unilinear, which can refer to anything arranged or developing along one line.
adjectiveRelating to or denoting descent or inheritance through a single line of ancestors, especially one parental line rather than both.
- Relating to descent or inheritance traced through a single line of ancestors, especially one parental line rather than both.
"The community preserved a unilineal system of descent, tracing its ancestry through one family line."
"The succession was unilineal, passing through the eldest branch of the family."
"Researchers used the unilineal inheritance pattern to trace the property's ownership through one ancestral line."
In a unilineal system, family history is followed through one ancestral line, not two.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unilineal come from?
Unilineal was formed in English from Latin uni-, meaning “one,” and lineal, an English word derived from Latin linealis and ultimately from linea, “line.” The combination expresses descent or connection along a single line. Its relatives lineal, linear, linearity, and collinear share the Latin root linea, reflecting the long Latin and English tradition of describing lines, alignment, and direct descent.
Related word forms
How unilineal is actually used
This is a formal, uncommon term used chiefly in anthropology, genealogy, and genetics. It is more specific than words such as linear and should not be used merely to mean straight or arranged in one line.
Easily confused with unilineal
Unilineal usually concerns descent or inheritance through a single ancestral line, whereas unilinear more generally means arranged or developing along one line and can also describe inheritance.