Under obligation, dropping rate fully? Only partially (8)
I believe the answer is:
grateful
'under obligation' is the definition.
(thesaurus)
'dropping rate fully? only partially' is the wordplay.
'partially' says the answer is hidden in the clue.
'GRATEFUL' can be found hidden inside 'dropping rate fully only'.
(Other definitions for grateful that I've seen before include "Showing gratitude" , "quantity of coal" , "Thankful, appreciative" , "Showing appreciation for kindness" , "Felt a rug (anag)" .)