make too low an estimate of; "he underestimated the work that went into the renovation"; "Don't underestimate the danger of such a raft trip on this river"
If you underrate someone or something, you do not recognize how clever, important, or significant they are. We women have a lot of good business skills, although we tend to underrate ourselves He underrated the seriousness of William's head injury. overrate + underrated under·rat·ed He is a very underrated poet