un·der·state 
/ˌʌndɚˈsteɪt/ verb
un·der·states; un·der·stat·ed; un·der·stat·ing /ˌʌndɚˈsteɪt/ verb [+ obj] : to say that (something) is smaller, less important, etc., than it really is
▪ He understated his taxable income. ▪ She's trying to understate the issue/problem.
▪ He understated his taxable income. ▪ She's trying to understate the issue/problem.
