Road on the way up had been submerged (7)
I believe the answer is:
drowned
'submerged' is the definition.
('drown' can be a synonym of 'submerge')
'road on the way up had' is the wordplay.
'road' becomes 'rd' (abbreviation).
'on the way up' says the letters should be written in reverse.
'had' becomes 'owned' ('own' can be a synonym of 'have').
'rd' back-to-front is 'dr'.
'dr'+'owned'='DROWNED'
'been' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for drowned that I've seen before include "Lost at sea" , "Died underwater" , "Submerged, flooded" , "Suffocated in water" , "Died by submersion" .)