Inside out? Stick with solution (5,4,3,3)
I believe the answer is:
under lock and key
'inside' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'out? stick with solution' is the wordplay.
I cannot really see how this works, but
'out?' could be 'under' (I've seen this in another clue) and 'under' is found in the answer.
'with' could be 'and' and 'and' is located in the answer.
'solution' could be 'key' (I've seen this in another clue) and 'key' is located in the answer.
The remaining letters 'lock' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for under lock and key that I've seen is " Imprisoned".)