Lawyer’s plain text nicked by men (10)
I believe the answer is:
prosecutor
'lawyer's' is the definition.
(prosecutor is a kind of lawyer)
'plain text nicked by men' is the wordplay.
'plain text' becomes 'prose' (I've seen this in another clue).
'nicked' becomes 'cut' (nick can mean to cut).
'by' says to put letters next to each other.
'men' becomes 'OR' (Other Ranks: non-commissioned soldiers).
'prose'+'cut'+'or'='PROSECUTOR'
(Other definitions for prosecutor that I've seen before include "One making case against defendant" , "Lawyer" , "originator of suit" , "Court official" , "One stating the case against a defendant" .)