On way up, came across independent couple (4)
I believe the answer is:
item
'couple' is the definition.
(a romantic couple are 'an item')
'on way up came across independent' is the wordplay.
'on way up' says the letters should be written in reverse.
'came' becomes 'met' (meeting is a kind of coming).
'across' means one lot of letters go next to another (across can mean on).
'independent' becomes 'i'.
'met'+'i'='meti'
'meti' in reverse letter order is 'ITEM'.
(Other definitions for item that I've seen before include "One thing - two people, perhaps" , "Piece of news: unit" , "section of magazine" , "Element" , "One of a series (or a couple!)" .)