Poles look around for the meaning (5)
I believe the answer is:
sense
'the meaning' is the definition.
('sense' can be a synonym of 'meaning')
'poles look around' is the wordplay.
'poles' becomes 'NS' (North and South poles).
'look' becomes 'see'.
'around' means one lot of letters goes inside another.
'ns' placed into 'see' is 'SENSE'.
'for' acts as a link.
(Other definitions for sense that I've seen before include "Meaning of a word or expression" , "eg Vision, hearing" , "Perceive, detect" , "Understanding" , "Hearing maybe" .)