Butcher's closed - accepting fine over a little infection (6)
I believe the answer is:
shufti
'butcher's' is the definition.
(butcher's and shufti can both mean a look)
'closed accepting fine over a little infection' is the wordplay.
'closed' becomes 'shut' (synonyms).
'accepting' indicates putting letters inside (inserted letters are accepted).
'fine' becomes 'f' (abbreviation in pencil classifications).
'over' is a charade indicator (letters next to each other) (in a down clue, some letters go over others).
'a little' indicates taking the first letters.
The initial letter of 'infection' is 'i'.
'shut' placed around 'f' is 'shuft'.
'shuft'+'i'='SHUFTI'
(Other definitions for shufti that I've seen before include "Informally, a brief inspection or look" , "Quick look or reconnoitre" , "eyeful" , "A quick look around, military term" , "Look (inf. from the Arabic)" .)