obtuse
她解释了三次他仍然不明白，真是个迟钝的人。
He still didn't understand after she explained three times—what an ___obtuse person.
这个三角形有一个底角是钝角。
One of the base angles of this triangle is ___obtuse.
他在会议上迟钝敷衍的回答引起了同事们的怀疑——他显然知道得比他承认的多。
His colleagues found his ___obtuse responses in the meeting suspicious—he clearly knew more than he admitted.