Serving men very roughly (2,2)

I believe the answer is:

or so

'roughly' is the definition.
(synonyms)

'serving men very' is the wordplay.
'serving men' becomes 'OR' (military abbreviation for Other Ranks).
'very' becomes 'so' (both can mean 'extremely').
'or'+'so'='OR SO'

(Other definitions for or so that I've seen before include "More or less" , "Approximately" , "Something like" , "roughly" .)

I've seen this clue in The Guardian.

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