Fiendly

Origin

Old English fēondliċ, corresponding to fiend + -ly.

Full definition of fiendly

Adjective

1. (obsolete) Hostile.
2. (now rare) Like a fiend; devilish.
• 1485, Thomas Malory, Le Morte Darthur, Book XI:Soo whan Sir Launcelot had lyffte up the tombe, there came oute an orryble and a fyendely dragon spyttynge wylde-fyre oute of hys mowthe.