1. [n]  a person who is entitled by law or by the terms of a will to inherit the estate of another
2. [n]  a person who inherits some title or office

1. \Heir\, n. [OE. heir, eir, hair, OF. heir, eir, F. hoir, L.
   heres; of uncertain origin. Cf. {Hereditary}, {Heritage}.]
   1. One who inherits, or is entitled to succeed to the
      possession of, any property after the death of its owner;
      one on whom the law bestows the title or property of
      another at the death of the latter.
            I am my father's heir and only son.   --Shak.
   2. One who receives any endowment from an ancestor or
      relation; as, the heir of one's reputation or virtues.
            And I his heir in misery alone.       --Pope.
   {Heir apparent}. (Law.) See under {Apparent}.
   {Heir at law}, one who, after his ancector's death, has a
      right to inherit all his intestate estate. --Wharton (Law
      Dict.).
   {Heir presumptive}, one who, if the ancestor should die
      immediately, would be his heir, but whose right to the
      inheritance may be defeated by the birth of a nearer
      relative, or by some other contingency.
   

2. \Heir\, v. t.
   To inherit; to succeed to. [R.]
         One only daughter heired the royal state. --Dryden.
   

Under the patriarchs the property of a father was divided among the sons of his legitimate wives (Gen. 21:10; 24:36; 25:5), the eldest son getting a larger portion than the rest. The Mosaic law made specific regulations regarding the transmission of real property, which are given in detail in Deut. 21:17; Num. 27:8; 36:6; 27:9-11. Succession to property was a matter of right and not of favour. Christ is the "heir of all things" (Heb. 1:2; Col. 1:15). Believers are heirs of the "promise," "of righteousness," "of the kingdom," "of the world," "of God," "joint heirs" with Christ (Gal 3:29; Heb. 6:17; 11:7; James 2:5; Rom. 4:13; 8:17).