HEIR (Lat. heres, from a root meaning to grasp, seen in herus or erus, master of a house, Gr. \dp, hand, Sans, hat ana, hand), in law, technically one who succeeds, by descent, to an estate of inheritance, in contradistinction to one who succeeds to personal property, i.e. next of kin. The word is now used generally to denote the person who is entitled by law to inherit property, titles, etc.,of another. The rules regulating the descent of property to an heir will be found in the articles INHERITANCE, SUCCESSION, etc.
An heir apparent (Lat. apparens, manifest) is he whose right of inheritance is indefeasible, provided he outlives the ancestor, e.g. an eldest or only son.
Heir by custom, or customary heir, he who inherits by a particular and local custom, as in borough-English, whereby the youngest son inherits, or in gavelkind, whereby all the sons inherit as parceners, and made but one heir.
Heir presumptive, one who is next in succession, but whose right is defeasible by the birth of a nearer heir, e.g. a brother or nephew, whose presumptive right may be destroyed by the birth of a child, or a daughter, whose right may be defeated by the birth of a son.
Special heir, one not heir at law (i.e. at common law), but by special custom.
Ultimate heir, he to whom lands come by escheat on failure of proper heirs. In Scots law the technical use of the word " heir " is not confined to the succession to real property, but includes succession to personal property as well.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)