Discharge sailor picked up by vehicle at hospital (7)
I believe the answer is:
catarrh
'discharge' is the definition.
(discharge in the nose or throat)
'sailor picked up by vehicle at hospital' is the wordplay.
'sailor' becomes 'tar' (tar can mean a sailor).
'picked up by' is an insertion indicator (some letters collected or picked up by others).
'vehicle' becomes 'car' (car is a kind of vehicle).
'at' is a charade indicator (letters next to each other).
'hospital' becomes 'H' (abbreviation for hospital on maps).
'tar' going inside 'car' is 'catarr'.
'catarr'+'h'='CATARRH'
(Other definitions for catarrh that I've seen before include "Arch rat with inflamed mucous membrane" , "Inflammation of membrane of nose and throat" , "Nasal inflammation" , "Arch rat with inflammation of mucous membrane" , "Nasal congestion" .)