myelinPronunciation: /ˈmʌɪəlɪn/Definition of myelin noun [mass noun] Anatomy & Physiology a mixture of proteins and phospholipids forming a whitish insulating sheath around many nerve fibres, which increases the speed at which impulses are conducted. Derivatives myelinated adjective myelinationPronunciation: /-ˈneɪʃ(ə)n/ noun Origin: late 19th century: from Greek muelos 'marrow' + -in1myelin in other Oxford dictionaries Definition of myelin in the US English dictionary
