Trying hard (7)
I believe the answer is:
onerous
I believe this is a double definition.
'trying' is the first definition.
(thesaurus)
'hard' is the second definition.
(I've seen this before)
(Other definitions for onerous that I've seen before include "Trying" , "Burdensome, oppressive" , "quite a burden if so" , "No euros? That's burdensome" , "Difficult, troublesome" .)