About fifty make casual visit to get material (6)
I believe the answer is:
poplin
'material' is the definition.
(I know that poplin is a type of material)
'about fifty make casual visit' is the wordplay.
I cannot really see how this works, but
'fifty' could be 'li' (I've seen this in other clues) and 'li' is found in the answer.
This explanation may well be incorrect...
'to get' is the link.
Can you help me to learn more?
(Other definitions for poplin that I've seen before include "Material" , "Strong plain-woven fabric" , "stuff!" , "Ribbed fabric" , "Corded cotton fabric" .)