Polish engineers penalise workers on time (10)
I believe the answer is:
refinement
'polish' is the definition.
(synonyms)
'engineers penalise workers on time' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'penalise' becomes 'fine'.
'workers' becomes 'men' (man is a kind of worker).
'on' means one lot of letters go next to another.
'time' becomes 't' (abbreviation).
're'+'fine'+'men'+'t'='REFINEMENT'
(Other definitions for refinement that I've seen before include "Improvement; elegance" , "culture" , "Cultivation" , "Elegance, sophistication" , "Polish" .)