Writing about tense traitor getting laid low (9)
I believe the answer is:
prostrate
'laid low' is the definition.
(thesaurus)
'writing about tense traitor' is the wordplay.
'writing' becomes 'prose' (prose is ordinary writing as opposed to poetry).
'about' indicates putting letters inside.
'tense' becomes 't' (grammatical abbreviation).
'traitor' becomes 'rat' (rat can mean a treacherous person).
't'+'rat'='trat'
'prose' enclosing 'trat' is 'PROSTRATE'.
'getting' acts as a link.
(Other definitions for prostrate that I've seen before include "Lying face downwards" , "Lying stretched out" , "Lying face-down" , "Flat" , "Totally exhausted" .)