Empty the reticule in case. It could wrinkle (6)
I believe the answer is:
crease
'wrinkle' is the definition.
(I know that wrinkle can be written as crease)
'empty the reticule in case' is the wordplay.
'empty' means to remove the middle letters.
'in' means one lot of letters goes inside another.
'reticule' with its middle removed is 're'.
're' going into 'case' is 'CREASE'.
'it could' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for crease that I've seen before include "Furrow; cricket line" , "found on cricket pitch" , "Cricket line; wrinkle" , "Cricket pitch marking" , "ruck" .)