• Slow of understanding; wanting readiness of apprehension; stupid; doltish; blockish. • Slow in action; sluggish; unready; awkward. • Insensible; unfeeling. • Not keen in edge or point; lacking sharpness; blunt. • Not bright or clear to the eye; wanting in liveliness of color or luster; not vivid; obscure; dim; as, a dull fire or lamp; a dull red or yellow; a dull mirror. • Heavy; gross; cloggy; insensible; spiritless; lifeless; inert. • Furnishing little delight, spirit, or variety; uninteresting; tedious; cheerless; gloomy; melancholy; depressing; as, a dull story or sermon; a dull occupation or period; hence, cloudy; overcast; as, a dull day. • To deprive of sharpness of edge or point. • To make dull, stupid, or sluggish; to stupefy, as the senses, the feelings, the perceptions, and the like. • To render dim or obscure; to sully; to tarnish. • To deprive of liveliness or activity; to render heavy; to make inert; to depress; to weary; to sadden. • To become dull or stupid.