Suspicious one boxed by Pandora, perhaps? (8)
I believe the answer is:
paranoid
'suspicious' is the definition.
(I've seen this before)
'one boxed by pandora perhaps?' is the wordplay.
'one' becomes 'I' (Roman numeral).
'boxed by' means one lot of letters goes inside another (I've seen this in other clues).
'perhaps?' indicates an anagram (I've seen 'perhaps' mean this).
'pandora' with letters rearranged gives 'paranod'.
'i' inserted inside 'paranod' is 'PARANOID'.
(Other definitions for paranoid that I've seen before include "Excessively suspicious" , "Paid Nora to have delusions?" , "one given to suspicion" , "Afflicted with delusions of persecution" , "Distrustful" .)