'isocortex' originates from a modern scientific combination of Greek and Latin: Greek 'iso-' (from Greek 'isos') meaning 'equal' and Latin 'cortex' meaning 'bark' or 'rind' (i.e., outer layer).

'isocortex' was coined in anatomical and neuroanatomical contexts in the late 19th to early 20th century as a term contrasting a more 'uniform' cortex with other cortical types; it has been used alongside and sometimes interchangeably with 'neocortex'.

Literally it combined the elements 'equal' + 'bark/outer layer', but over time it came to denote the specific, relatively uniform six-layered cerebral cortex of mammals (the modern anatomical meaning).