Having gone without one to open up and take a look (6)
I believe the answer is:
glance
'a look' is the definition.
(I know that glance is a more specific form of the action look)
'having gone without one to open' is the wordplay.
'having' becomes 'lance' (I can't justify this - if you can you should give a lot more credence to this answer).
'without' indicates named letters should be taken away.
'to open' is a charade indicator (letters next to each other) (some letters go before or 'open' others).
'gone' with 'one' taken out is 'g'.
'lance' put after 'g' is 'GLANCE'.
'up and take' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for glance that I've seen before include "Momentary look" , "Oblique impact" , "Give a quick look" , "Take a brief or hurried look" , "it has a metallic lustre" .)