Stiff spanner found in hovel (7)
I believe the answer is:
starchy
'stiff' is the definition.
('starchy' can be a synonym of 'stiff')
'spanner found in hovel' is the wordplay.
'spanner' becomes 'arch' (I've seen this before).
'found in' is an insertion indicator.
'hovel' becomes 'sty' (I've seen this in other clues).
'arch' put inside 'sty' is 'STARCHY'.
(Other definitions for starchy that I've seen before include "Unbending" , "Conventional" , "Stiff, like potatoes" , "Stiff, formal" , "Stiff and formalistic" .)