alkyl

adj. containing an alkyl group (Chemistry)

An alkyl is a univalent (or free) radical containing only carbon and hydrogen atoms arranged in a chain. The alkyls form a homologous series with the general formula CnH2n+1. Examples include methyl, CH3· (derived from methane) and butyl C4H9· (derived from butane). They are normally not found on their own but are found as part of larger branched chain organic molecules. On their own they are free radicals and therefore extremely reactive.
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Alkyl /al·kyl/ the monovalent radical formed when an aliphatic hydrocarbon loses one hydrogen atom. al·kyl n. [more]Alkyl - Community and Resources

Noun
1. any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons
(synonym) alkyl group, alkyl radical
(hypernym) group, radical, chemical group
(hyponym) ethyl, ethyl group, ethyl radical

 Say it 
(-CnH2n+1). A molecular fragment derived from an alkane by dropping a hydrogen atom from the formula. Examples are methyl (CH3) and ethyl (CH2CH3).