Hi tombola, an extract from Dictionary.com
fell
3 [fel] Show IPA
adjective
1.
fierce; cruel; dreadful; savage.
2.
destructive; deadly: fell poison; fell disease.
Idioms
3.
at / in one fell swoop. swoop ( def 5 ) .
Origin:
1250–1300; Middle English fel < Old French, nominative of felon wicked. See felon
Related forms
fell·ness, noun
fell
4 [fel] Show IPA
noun
the skin or hide of an animal; pelt.