substituted

Substituted is the adjective form of substitute. It generally indicates that something has been replaced by a substitute or that a component has been replaced by a different one. It is used across disciplines to denote an alternative or a replacement.

In chemistry, a substituted compound has one or more substituents—atoms or groups that have replaced hydrogen or another atom on a core structure. Substituted hydrocarbons include alkyl, halogen, or functional groups; examples: chlorobenzene (chlorine-substituted benzene) and methyl-substituted toluene. The term substituent is central to describing the structure and properties of these compounds.

In mathematics and logic, substitution refers to replacing a variable with an expression or value within an equation or expression. It is a core technique in solving linear and algebraic equations, in integration, and in various proof systems. In cryptography, a substitution cipher encodes plaintext by substituting each symbol with another.

In biology and genetics, a substitution mutation is a change of a single nucleotide that leads to a different amino acid in a protein, potentially altering function. In population genetics, substitutions accumulate over time and are used in phylogenetic analyses.

In sports and everyday language, substituted describes a player who has been brought on to replace another player during a game, or more broadly something that has been replaced by a substitute.