'epidermal' originates from Greek, specifically the word 'epidermis,' where 'epi-' meant 'upon' and 'derma' meant 'skin.'

'epidermis' transformed into the Latin word 'epidermis,' and eventually became the modern English word 'epidermal' through Middle English.

Initially, it meant 'upon the skin,' but over time it evolved into its current meaning of 'relating to the outer layer of the skin.'