transitive. To make (the eyes or ears) dull; (also) to harden (the heart).

transitive. To blunt, deaden, dull the sensation of; to deprive of sharpness or vigour.

To render less sensitive; to take away the keenness of, blunt (the bodily senses or organs).

To take off the sharpness of, to blunt (an edge or point, or something edged or pointed). Often figurative in to dull the edge of = 3b.

transferred. To dim (the sight or other senses, the perception, or judgement), so that they no longer receive or form distinct impressions.

transitive. To render dull, to dull.

transitive. To make dull or blunt.