Move like sap (4)
I believe the answer is:
ooze
'move like sap' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ooze that I've seen before include "Flow out slowly or thickly" , "Exude mud" , "Leak - slimy mud" , "Slime" , "Seep out slowly" .)