Some cannibals appearing in wood (5)
I believe the answer is:
balsa
'wood' is the definition.
(balsa is a kind of wood)
'some cannibals appearing in' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'BALSA' is hidden within 'cannibals appearing in'.
(Other definitions for balsa that I've seen before include "Tree with light soft wood" , "Strong lightweight wood" , "Very lightweight wood from tropical tree" , "A slab (anag.)" , "Raft-making S American corkwood" .)