Definition of aliphatic in US English:



  • Relating to or denoting organic compounds in which carbon atoms form open chains (as in the alkanes), not aromatic rings.

    Compare with alicyclic
    • ‘These included formaldehyde, several other aldehydes, ketones, aliphatic and aromatic hydrocarbons, glycol ethers, organic acids, and alcohols.’
    • ‘Aromatic and aliphatic polyurethanes share the following properties that make them suitable for use in medical devices.’
    • ‘For example, alkyl groups can be introduced into aliphatic hydrocarbons or aromatic hydrocarbons by alkylation reactions.’
    • ‘The most relevant candidate for this kind of investigation is 19 F-labeled tryptophan, besides other aromatic and aliphatic amino acids.’
    • ‘The majority of substances identified were aliphatic or aromatic hydrocarbons.’


usually aliphatics
  • An aliphatic compound.

    • ‘Focusing on aliphatics, this series can be further divided into families called homologous series of compounds.’
    • ‘Aliphatics are our company's range of hydrocarbon fluids including specialty brands.’
    • ‘For the chlorinated aliphatics industry, the main data to be collected will be clarifications to survey information, and possibly site visits.’
    • ‘Pesticide organochlorines are diphenyl aliphatics previously used to control insect vector infections.’
    • ‘The characteristic that distinguishes benzene from the aliphatics and alicyclics, and that defines the aromatics, is the arrangement of electrons in the ring.’


Late 19th century (originally used of the fatty acids): from Greek aleiphar, aleiphat- ‘fat’ + -ic.