1. The state of being the firstborn of the same parents; seniority by birth among children of the same family.
2. (Eng. Law) Defn: The exclusive right of inheritance which belongs to the eldest son. Thus in England the right of inheriting the estate of the father belongs to the eldest son, and in the royal family the eldest son of the sovereign is entitled to the throne by primogeniture. In exceptional cases, among the female children, the crown descends by right of primogeniture to the eldest daughter only and her issue.
the right, by law or custom, of the firstborn legitimate son to inherit his parent's entire or main estate, in preference to shared inheritance among all or some children, a child other than the eldest male, a daughter, illegitimate child or a collateral relative. In some cases the estate may instead be the inheritance of the firstborn child or occasionally the firstborn daughter.
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Not to inherit by right of primogeniture, gavelkind or borough English, or possess in perpetuity an extensive demesne of a sufficient number of acres, roods and perches, statute land measure (valuation 42 pounds), of grazing turbary surrounding a baronial hall with gatelodge and carriage drive nor,
James Joyce. Ulysses
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Solomon found time to reflect that Jonah was undeserving, and Jonah to abuse Solomon as greedy; Jane, the elder sister, held that Martha's children ought not to expect so much as the young Waules; and Martha, more lax on the subject of primogeniture, was sorry to think that Jane was so "having."