Lowly worker mostly impudent when turning up (4)
I believe the answer is:
serf
'lowly worker' is the definition.
(I've seen this in another clue)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for serf that I've seen before include "Feudal labourer" , "Feudal estate worker" , "who got into bondage" , "Slave" , "Peasant, agricultural labourer" .)