noun
    
    plural flaps
    
    [count] a flat piece of material that is attached to something on one side and that can be easily moved
    
    
    
    
    
    
    
    the movement or sound of something that is moving up and down or back and forth
    
    
    
    
    
    informal
    
    a state or situation in which many people are excited or upset
    
    
    
    b chiefly Brit :a state in which someone is very upset
    
    
    
    a movable part of an airplane wing that can be raised or lowered and that is used to increase lift
    
    verb
    
    flaps; flapped; flapping
    
    to move (something) up and down or back and forth [+ obj]