A rapidly replaced stoneworker (8)
I believe the answer is:
lapidary
'stoneworker' is the definition.
I can't tell whether this defines the answer.
'a rapidly replaced' is the wordplay.
'replaced' indicates anagramming the letters.
'a'+'rapidly'='arapidly'
'arapidly' anagrammed gives 'LAPIDARY'.
Can you help me to learn more?
(Other definitions for lapidary that I've seen before include "(Of language) elegant and concise" , "Designer and cutter of gems" , "in commemorative style" , "using concise language" , "Arid play with engraver of gems" .)