'axonic' originates from Modern scientific formation based on the noun 'axon' (from Greek 'axōn'), with the adjectival suffix '-ic' meaning 'pertaining to'.

'axon' entered English from New Latin/Modern Latin 'axon', which itself comes from Greek 'axōn' meaning 'axis'; later the scientific adjective 'axonic' was formed by adding the suffix '-ic' to 'axon' in 19th–20th century anatomical/neuroscientific usage.

Initially the Greek root 'axōn' meant 'axis' (or 'axle'); over time 'axon' came to denote the nerve fiber in anatomy and neuroscience, and 'axonic' evolved to mean 'pertaining to an axon'.