'dialectal' originates from the Greek word 'dialektos', where 'dia-' meant 'through' and 'legein' meant 'to speak'.

'dialektos' transformed into the Latin word 'dialectus', and eventually became the modern English word 'dialectal' through Middle English.

Initially, it meant 'a form of speech', but over time it evolved into its current meaning of 'relating to a dialect'.