Gritty queen and spare king finally moving forward (8)
I believe the answer is:
granular
'gritty' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for granular that I've seen before include "Made of small particles" , "Consisting of small hard particles" , "Particulate" , "Like grains or hard particles" , "Gritty (like some sugar?)" .)