Dull, v. t. [imp. & p. p. Duller p. pr. & vb. n. Dulling.]
 1. To deprive of sharpness of edge or point. “This . . . dulled their swords.”
    Borrowing dulls the edge of husbandry.   --Shak.
 2. To make dull, stupid, or sluggish; to stupefy, as the senses, the feelings, the perceptions, and the like.
 Those [drugs] she has
 Will stupefy and dull the sense a while.   --Shak.
    Use and custom have so dulled our eyes.   --Trench.
 3. To render dim or obscure; to sully; to tarnish. “Dulls the mirror.”
 4. To deprive of liveliness or activity; to render heavy; to make inert; to depress; to weary; to sadden.
    Attention of mind . . . wasted or dulled through continuance.   --Hooker.