Crossword Genius

Swore a lawman will hold steady (8)

Ross

I believe the answer is:

affirmed

'swore' is the definition.
('affirm' can be a synonym of 'swear')

'a lawman will hold steady' is the wordplay.
'lawman' becomes 'fed' (fed can informally mean a federal agent).
'will hold' means one lot of letters goes inside another (inserted letters are held inside).
'steady' becomes 'firm' (similar in meaning).
'fed' enclosing 'firm' is 'ffirmed'.
'a'+'ffirmed'='AFFIRMED'

(Other definitions for affirmed that I've seen before include "Averred" , "Declared solemnly to be true" , "Stated as a fact" , "Endorsed" , "Stated emphatically" .)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app