Continues to be stiff? (7)
I believe the answer is:
remains
This clue is a double definition.
'continues' is the first definition.
(remaining is a kind of continuing)
'stiff?' is the second definition.
('remains' can be a synonym of 'stiff')
'to be' acts as a link.
(Other definitions for remains that I've seen before include "surviving old parts" , "Continues" , "Remnants" , "What's left (maybe of a body)" , "Residue" .)