past tense of 1fall
verb
fells; felled; felling
[+ obj] to cut down (a tree)
to beat or knock down (someone or something)
adjective
formal + literary :very fierce or cruel
in one fell swoop
also at one fell swoop
with a single, quick action or effort
noun
plural fells
[count] Brit
a hill in the north of England
a high field or moor in the north of England