Hidden? With lid off, open to view (5)
I believe the answer is:
overt
'open to view' is the definition.
(I've seen this before)
'hidden? with lid off' is the wordplay.
'hidden?' becomes 'vert' (I can't justify this - if you can you should give a lot more credence to this answer).
'with' is a charade indicator (letters next to each other).
'lid' suggests taking the first letters (I've seen 'lid of' mean this (in a down clue, the lid could be the top letter)).
The initial letter of 'off' is 'o'.
'vert' put after 'o' is 'OVERT'.
Can you help me to learn more?
(Other definitions for overt that I've seen before include "Explicit" , "Open and unconcealed" , "Patent, evident" , "Done in an obvious way" , "Openly displayed" .)