'dullified' originates from English, specifically from the verb 'dullify', where the base 'dull' comes from Old English roots meaning 'foolish' or 'blunt' and the suffix '-ify' (from Latin via Old French) means 'to make or cause to be'.

'dull' changed from Old English 'dol' or 'doll' (meaning 'foolish' or 'stupid') into Middle English 'dul' with senses shifting toward 'not sharp' or 'lacking brightness'; later the productive suffix '-ify' (from Latin '-ificare' via Old French '-ifier') was added to form 'dullify', and 'dullified' is the past/past-participle form.

Initially, roots related to 'dull' carried senses of 'stupid' or 'insensible'; over time the sense shifted toward 'not sharp, lacking brightness or liveliness', and 'dullified' now means 'made less sharp, lively, or intense'.