'hateful' originates from Old English and the adjective-forming suffix '-ful'. It is formed from the verb 'hate' (Old English 'hātian' / 'hatan'), where the root 'hāt' meant 'hatred' or 'hate', combined with Old English 'ful' meaning 'full of'.

'hate' comes from Old English 'hātian' (verb) and related forms; in Middle English the word became 'hate'. The adjective 'hateful' was formed by adding the suffix '-ful' in late Middle English and developed into the modern English form 'hateful'.

Initially it meant 'full of hate' (literally 'having hate'), and over time the sense has remained but broadened to include 'very unpleasant' or 'detestable' in general use.