Examine outside of every individual wooden box (3,5)
I believe the answer is:
tea chest
'wooden box' is the definition.
(I've seen this before)
'examine outside of every individual' is the wordplay.
'examine' becomes 'test' (synonyms).
'outside of' means one lot of letters goes inside another.
'every individual' becomes 'each' (I've seen this before).
'test' placed around 'each' is 'TEA-CHEST'.
(Other definitions for tea chest that I've seen before include "box of gunpowder, say" , "packing-case" , "Holder of leaves for brewing?" , "Leaves box" , "Item famously thrown overboard" .)