'stultify' originates from Latin, specifically the word 'stultificare,' where 'stultus' meant 'foolish' and the element '-ficare' (from 'facere') meant 'to make'.

'stultify' changed from Late Latin 'stultificare' and passed through Medieval/Anglo-Norman and early modern usage (and influence from French 'stultifier') before becoming the modern English 'stultify'.

Initially, it meant 'to make or show to be foolish,' but over time it also acquired the sense 'to render ineffective, useless, or to sap enthusiasm', which is common in modern usage.