noun
    
    plural -ils
    
    somewhat formal + literary
    
    [noncount] :the possibility that you will be hurt or killed or that something unpleasant or bad will happen :danger
    
    
    
    usually used in the phrase in peril
    
    
    
    
    
    
    
    [count] :something that is likely to cause injury, pain, harm, or loss :danger
    
    
    
    usually plural
    
    
    
    
    
    at your (own) peril
    
    used to say that if you do something you should be aware that it is dangerous and that you could be harmed, injured, punished, etc.