substituent

An atom or group substituted for another in a chemical compound.

Of or relating to such an atom or group.

That which substitutes; in chem., an atom or atomic group which takes the place of another atom or group present in the molecule of the original compound. Thus in the compounds methane (CH₄) and methyl alcohol (CH₃OH), OH is said to be the substituent.

Any atom, group, or radical substituted for another, or entering a molecule in place of some other part which is removed.

any atom, group, or radical substituted for another, or entering a molecule in place of some other part which is removed