(刀等)钝的

呆滞的

不活跃的（dull的比较级）

a lacking in liveliness or animation

a emitting or reflecting very little light

s being or made softer or less loud or clear

s so lacking in interest as to cause mental weariness

s (of color) very low in saturation; highly diluted

a not keenly felt

s slow to learn or understand; lacking intellectual acuity

s (of business) not active or brisk

a not having a sharp edge or point

s blunted in responsiveness or sensibility

s not clear and resonant; sounding as if striking with or against something relatively soft

s darkened with overcast