Could make a mess of material connections (5)
I believe the answer is:
seams
'material connections' is the definition.
'seams' can be an answer for 'connections' (seam is a kind of connection). I am not sure about the 'material' bit.
'could make a mess' is the wordplay.
'could make' is an anagram indicator.
'a'+'mess'='amess'
'amess' anagrammed gives 'SEAMS'.
'of' is the link.
Can you help me to learn more?
(Other definitions for seams that I've seen before include "Joints" , "Strata of ore or coal suitable for mining" , "Sewn joins" , "Strata of minerals" .)