Corrects editor covering soldiers with sarcasm at first (6)
I believe the answer is:
emends
'corrects' is the definition.
(I've seen this before)
'editor covering soldiers with sarcasm at first' is the wordplay.
'editor' becomes 'ed' (abbreviation).
'covering' means one lot of letters goes inside another.
'soldiers' becomes 'men' (men can mean a group of soldiers).
'with' is a charade indicator (letters next to each other).
'at first' says to take the initial letters.
The initial letter of 'sarcasm' is 's'.
'ed' going around 'men' is 'emend'.
'emend'+'s'='EMENDS'
(Other definitions for emends that I've seen before include "Makes corrections in written material" , "Makes corrections in written or printed copy" , "Makes improvements or corrections" , "Send me (anag.); corrects" , "Edits text" .)