Not fine -- initially grey then wet (6)
I believe the answer is:
grainy
'not fine' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I can't see?
'initially grey then wet' is the wordplay.
'initially' suggests taking the first letters.
'then' says to put letters next to each other.
'wet' becomes 'rainy' ('rainy' can be similar in meaning to 'wet'**).
The initial letter of 'grey' is 'g'.
'g'+'rainy'='GRAINY'
Can you help me to learn more?
(Other definitions for grainy that I've seen before include "(Of photo) having low resolution" , "gravelly" , "Old still can be this" , "Gritty" , "Granular" .)