Cross pass through crossing both poles (10)
I believe the answer is:
transverse
'cross' is the definition.
(synonyms)
'pass through crossing both poles' is the wordplay.
'pass through' becomes 'traverse'.
'crossing' means one lot of letters goes inside another.
'both poles' becomes 'ns' (North and South poles. I am not sure about the 'both' bit.).
'traverse' placed around 'ns' is 'TRANSVERSE'.
Can you help me to learn more?
(Other definitions for transverse that I've seen before include "Extending across something" , "Crossing" , "Extending across (the long axis)" , "Cross" , "go in 6 ac [CRISSCROSS]" .)