fiendly

The story

1. Old English · inherited fromfēondliċ“hostile”
2. Middle English · inherited fromfendly
3. English todayfiendly

From Middle English fendly, feendly (“hostile, devilish”), from Old English fēondliċ (“hostile”), corresponding to fiend + -ly. Cognate with Dutch vijandelijk (“hostile”), German feindlich (“hostile”), Danish fjendtlig (“hostile”), Swedish fiendtlig, fientlig (“hostile”).