Afflicted former nurse concealing subterfuge (8)
I believe the answer is:
stricken
'afflicted' is the definition.
(I know that afflicted can be written as stricken)
'former nurse concealing subterfuge' is the wordplay.
'former nurse' becomes 'SEN' (state registered nurse - former UK nurse title).
'concealing' means one lot of letters goes inside another.
'subterfuge' becomes 'trick' (subterfuge is trickery or deceit).
'sen' going around 'trick' is 'STRICKEN'.
(Other definitions for stricken that I've seen before include "Overcome by grief or shock" , "Laid low (by illness)" , "Afflicted or expunged from the record" , "Seriously affected (by, eg, condition)" , "Severely afflicted" .)