Rod, pole or perch (5)
I believe the answer is:
roost
'perch' is the definition.
(I know that perch can be written as roost)
'rod pole' is the wordplay.
I cannot quite see how this works, but
'pole' could be 's' (abbreviation for South, as in South Pole) and 's' is located in the answer.
The remaining letters 'root' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'or' acts as a link.
Can you help me to learn more?
(Other definitions for roost that I've seen before include "where fliers land" , "Night spot for birds/bats" , "Where birds rest at night" , "It's sometimes ruled" , "(Bird) settle for night" .)