More fancy following golf? It's long and really slow-moving! (7)
I believe the answer is:
glacier
'it's long and really slow-moving' is the definition.
(a glacier moves very slowly)
'more fancy following golf?' is the wordplay.
'more fancy' becomes 'lacier' ('lacy' can be similar in meaning to 'fancy').
'following' is a charade indicator (letters next to each other).
'golf?' becomes 'g' (phonetic alphabet: alpha, bravo, charlie etc.).
'lacier' put after 'g' is 'GLACIER'.
(Other definitions for glacier that I've seen before include "Slow-moving flow of ice" , "One creeps downhill" , "Moving body of ice" , "Slow-moving mass of ice" , "Creeping ice mass" .)