Professed chief spotted scratching head (10)
I believe the answer is:
maintained
'professed' is the definition.
'chief spotted scratching head' is the wordplay.
'chief' becomes 'main' (I've seen this before).
'spotted' becomes 'stained' ('stain' can be a synonym of 'spot').
'scratching head' means to remove the first letter.
'stained' with its initial letter taken away is 'tained'.
'main'+'tained'='MAINTAINED'
(Other definitions for maintained that I've seen before include "being kept going" , "Insisted" , "Sustained" , "Kept up (level)" , "Declared; supported" .)