Pauper getting jab in popular hospital department (8)
I believe the answer is:
indigent
'pauper' is the definition.
(thesaurus)
'jab in popular hospital department' is the wordplay.
'jab' becomes 'dig' ('dig' can be a synonym of 'jab').
'in' indicates putting letters inside.
'popular' becomes 'in'.
'hospital department' becomes 'ent'.
'in'+'ent'='inent'
'dig' placed inside 'inent' is 'INDIGENT'.
'getting' acts as a link.
(Other definitions for indigent that I've seen before include "Poor and needy" , "Poor enough to need help from others" , "poor fellow" , "Impoverished, destitute" , "Needy, poverty-stricken" .)