underrate
/ˌʌndəˈreɪt ˌअन्डˈरेट्/ verb [T] to think that somebody/something is less clever, important, good, etc. than he/she/it really is किसी को वास्तविकता से कम चतुर, बड़ा, अच्छा आदि समझना
✪ विलोम overrate