Constituent blasted dingier hospital department (10)
I believe the answer is:
ingredient
'constituent' is the definition.
(ingredient is a kind of constituent)
'blasted dingier hospital department' is the wordplay.
'blasted' indicates an anagram.
'hospital department' becomes 'ent'.
'dingier' anagrammed gives 'ingredi'.
'ingredi'+'ent'='INGREDIENT'
(Other definitions for ingredient that I've seen before include "bit of meal?" , "Something required for a recipe" , "Constituent" , "Item in a recipe" , "Component element" .)