Poles wish to inform (6)
I believe the answer is:
snitch
'inform' is the definition.
(I've seen this before)
'poles wish' is the wordplay.
'poles' becomes 'SN' (North and South poles).
'wish' becomes 'itch' (I have seen 'Nagging wish ' mean 'itch' so perhaps 'wish' could also mean 'itch').
'sn'+'itch'='SNITCH'
'to' is the link.
(Other definitions for snitch that I've seen before include "Steal; inform (on someone)" , "Inform on someone in slangy way" , "who tells on his classsmate?" , "Police informer" , "Inform on, tell tales" .)