American journey without end lacking interest (4)
I believe the answer is:
arid
'without end lacking interest' is the definition.
I can't judge whether this definition defines the answer.
'american journey' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'journey' becomes 'rid' (I am not sure about this - if you are sure you should believe this answer much more).
'a'+'rid'='ARID'
Can you help me to learn more?
(Other definitions for arid that I've seen before include "Parched with heat" , "Dry, devoid of interest" , "Without much rainfall" , "(Of climate) dry" , "Without water" .)