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