The term 'dunce cap-shaped' can be described by two crossword solutions: CONIC (5 letters) and conoid (6 letters). A CONIC is a geometric shape that is created by intersecting a cone with a plane. A conoid is a three-dimensional shape that is similar to a cone, but with a curved surface instead of a straight one. Both of these shapes are similar to the traditional dunce cap, which is a pointed hat that was historically used to shame students who were not performing well in school.