fiendishly
Concise Oxford English Dictionary © 2008 Oxford University Press:
fiendish/ˈfiːndɪʃ/
▶adjective
- 1 extremely cruel or unpleasant.
- 2 informal extremely complex.
– derivatives
fiendishly adverb,
fiendishness noun.
fiendishly adverb,
fiendishness noun.
'fiendishly' also found in these Oxford entries:

