n. The act of substituting, or putting (one person or thing) in the place of another; also, the state or fact of being substituted.n. The office of a substitute: delegated authority.n. In grammar, the use of one word for another; syllepsis.n. In Roman law, the effect of appointing a person to be heir, in case the heir first nominated would not or could not be heir.n. In French law, a disposition of property whereby the person receiving it, who is called the institute (le grévé), is charged either at his death or at some other time to deliver it over to another person called the substitute (l'appelé).n. In chem., the replacing of one or more elements or radicals in a compound by other elements or radicals.n. In algebra: The act of replacing a quantity by another equal to it; also, in the language of some algebraists, the replacement of a set of variables by another set connected with the first by a system of equations equal in number to the number of variables in each set. See transformation (which is the better term).n. The operation of changing the order of a finite number of objects, generally letters, that are in a row, the change following a rule according to which the object in each place is earned to some definite place in the row, this operation being regarded as itself a subject of algebraical operations.n. A linear transformation.n. In biology: The assumption by one organ of a function which was at one time performed by another organ. Thus the swim-bladder in fishes shows “that an organ originally constructed for one purpose, namely, notation, may be converted into one for a wholly different purpose, namely respiration.”n. The acquisition by an organ of a secondary function which, at first performed incidentally, may gradually become the chief function if the primary function becomes useless or is performed by another organ. Thus “the little folds of skin which originally served as ovigerous frena, but which, like-wise, very slightly aided the act of respiration, have been gradually converted by natural selection into branchiæ, simply through an increase in their size and the obliteration of their adhesive glands.”n. In Scots law, a technical enumeration of a series of heirs.n. In civil law, the appointment, in a will, of a successor to a devisee or legatee; subrogation.
