Related Clues:

• Slow-witted - tedious - cloudy
• Unlikely to cut
• Far from vivid
• Mind-numbing
• Not interesting
• Hard to cut with
• Like some finishes
• In need of sharpening
• Not a very interesting Constable?
• Lacking excitement
• Matt
• Matt; overcast
• Boring day for classes at Eton, say - double Latin
• Grey is boring
• Lacklustre