'roughen' originates from English, specifically the word 'rough', where 'rough' meant 'having an uneven or irregular surface'. The suffix '-en' is used to form verbs meaning 'to make or become'.

'roughen' was formed in English by adding the verb-forming suffix '-en' to 'rough', and eventually became the modern English word 'roughen'.

Initially, it meant 'to make rough or become rough', and this meaning has remained the same in modern usage.