What many in panic make themselves (6)
I believe the answer is:
scarce
'what many' is the definition.
I can't judge whether this definition defines the answer.
'in panic make themselves' is the wordplay.
'in' means one lot of letters goes inside another.
'panic' becomes 'scare' (synonyms).
'make themselves' becomes 'c' (I can't explain this - if you can you should believe this answer much more).
'scare' enclosing 'c' is 'SCARCE'.
Can you help me to learn more?
(Other definitions for scarce that I've seen before include "Not often found" , "Not enough to meet demand" , "Wanting" , "Hard to obtain" , "Like gold dust" .)