Joined female journalist crossing United States (5)
I believe the answer is:
fused
'joined' is the definition.
(fused means joined together)
'female journalist crossing united states' is the wordplay.
'female' becomes 'f' (common abbreviation).
'journalist' becomes 'ed' (short for editor).
'crossing' indicates putting letters inside (to cross can mean to go over or around).
'united states' becomes 'US' (abbreviation for the United States).
'f'+'ed'='fed'
'fed' placed around 'us' is 'FUSED'.
(Other definitions for fused that I've seen before include "Stuck together" , "Combined" , "Welded together by heat" , "Married" , "in one piece" .)