Police in small wood appearing endlessly (4)
I believe the answer is:
cops
'police' is the definition.
(cop can informally mean a police officer)
'in small wood appearing endlessly' is the wordplay.
'in' means one lot of letters goes inside another.
'small wood' becomes 'cos' (I can't justify this - if you can you should believe this answer much more).
'appearing' becomes 'jumping' (jumping is a kind of appearing).
'endlessly' indicates the central letters (the ends of the words are removed).
The centre of 'jumping' is 'p'.
'cos' going around 'p' is 'COPS'.
Can you help me to learn more?
(Other definitions for cops that I've seen before include "Panda owners" , "Familiar American policemen" , "The police (sl.)" , "Police (slang)" .)