(A) civil law. In the law of devises, it is the putting of one person in the place of another, so that he may, in default of ability in the former, or after him, have the benefit of a devise or legacy. 2. It is a species of subrogation made in two different ways; the first is direct substitution, and the latter a trust or fidei commissary substitution. The first or direct substitution, is merely the institution of a second legatee, in case the first should be either incapable or unwilling to accept the legacy; for example, if a testator should give to Peter his estate, but in case he cannot legally receive it, or he willfully refuses it, then I give it to Paul; this is a direct substitution. Fidei commissary substitution is that which takes place when the person substituted is not to receive the legacy until after the first legatee, and consequently must receive the thing bequeathed from the hands of the latter for example, I institute Peter my heir, and I request that at his death he shall deliver my succession to Paul. (B) chancery practice. This takes place in a case where a creditor has a lien on two different parcels of land, and another creditor has a subsequent lien on one only of the parcels, and the prior creditor elects to have his whole demand out of the parcel of land on which the subsequent creditor takes his lien; the latter is entitled, by way of substitution, to have the prior lien assigned to him for his benefit.
Law Dictionary – Alternative Legal Definition
In the civil law. The putting one person in place of another; particularly, the act of a testator in naming a second devisee or legatee who is to take the bequest either on failure of the original devisee or legatee or after him. In Scotch law. The enumeration or designation of the heirs in a settlement of property. Substitutes in an entail are those heirs who are appointed in succession on failure of others.