An alkylator is an any agent which helps to add one or more alkyl groups to a compound in the process of reacting with an alkylating agent, espcially one which alkylates a nucleic acid.
An alkylation is any reaction in which an alkyl group is added to a molecule, used in the production of high-octane petroleum fuels.
An alkyl is any of a series of univalent radicals of the general formula CnH2n+1 derived from aliphatic hydrocarbons.