Inward movement in the return of a predator (6)
I believe the answer is:
inflow
'inward movement' is the definition.
The definition and answer can be both natural processes as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'in the return of a predator' is the wordplay.
'the return of' says the letters should be written in reverse.
'a predator' becomes 'wolf'.
'wolf' in reverse letter order is 'flow'.
'in'+'flow'='INFLOW'
Can you help me to learn more?
(Other definitions for inflow that I've seen before include "Arrival of air or water" , "Influx" , "Maybe immigrants" , "People arriving, say" , "Fluid movement" .)