Digging in during a bygone dynasty (6)
I believe the answer is:
mining
'digging' is the definition.
(thesaurus)
'in during a bygone dynasty' is the wordplay.
'during' is an insertion indicator.
'a bygone dynasty' becomes 'ming' (Chinese dynasty. I am not sure about the 'bygone' bit.).
'in' going inside 'ming' is 'MINING'.
Can you help me to learn more?
(Other definitions for mining that I've seen before include "Excavating (ores)" , "Excavating (coal, ore)" , "non-renewable industry" , "Extracting ores or coal from the earth" , "Laying down explosives" .)