Look closed outside, finally opening before one (6)
I believe the answer is:
shufti
'look' is the definition.
(a quick or furtive look)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for shufti that I've seen before include "Colloquial word for look" , "Peep (from the Arabic)" , "Quick look or reconnoitre" , "Quick look round" , "Glance (colloq.)" .)