Turning up on regular basis, Kantism provides valuable material (4)
I believe the answer is:
mink
'valuable material' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'turning up on regular basis kantism' is the wordplay.
'turning up' shows that the letters should be reversed in order.
'on regular basis' indicates alternate letters (letters selected at regular intervals).
The alternate letters of 'kantism' are 'knim'.
'knim' in reverse letter order is 'MINK'.
'provides' is the link.
Can you help me to learn more?
(Other definitions for mink that I've seen before include "(Animal prized for its) fur" , "Animal farmed for fur" , "(Fur from) destructive animal" , "Rodent bred for fur" , "Weasel relative (or its fur)" .)