Passing across trade is tricky (7)
I believe the answer is:
astride
'passing across' is the definition.
(I've seen this before)
'trade is tricky' is the wordplay.
'tricky' is an anagram indicator.
'trade'+'is'='tradeis'
'tradeis' anagrammed gives 'ASTRIDE'.
(Other definitions for astride that I've seen before include "On top of" , "on horseback" , "On the back of" , "Straddling (horse)" , "With legs stretched apart - tirades (anag)" .)