Couple split over America changing direction ... (4)
I believe the answer is:
pair
'couple split' is the definition.
'pair' can be an answer for 'couple' (synonyms). I am unsure of the 'split' bit.
'over america changing direction' is the wordplay.
'over' means one lot of letters goes inside another.
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'changing' becomes 'pi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'direction' becomes 'r' (r is abbreviation for right).
'a' put inside 'pi' is 'pai'.
'pai'+'r'='PAIR'
Can you help me to learn more?
(Other definitions for pair that I've seen before include "Two of a similar type" , "Couple - wed" , "Husband and wife" , "item" , "Set of two" .)