understatement
    /ˌʌndɚˈsteɪtmənt/ 
    
 
    
    noun
    
    plural -ments
    
    [count] :a statement that makes something seem smaller, less important, etc., than it really is
    
    
    
    
    
    [noncount] :the practice of describing things in a way that makes them seem smaller, less important, etc., than they really are