Flea damaged part of tree (4)
I believe the answer is:
leaf
'part of tree' is the definition.
'leaf' can be an answer for 'part' (leaf is a kind of part). I am not sure about the 'of tree' bit.
'flea damaged' is the wordplay.
'damaged' is an anagram indicator.
'flea' with letters rearranged gives 'LEAF'.
Can you help me to learn more?
(Other definitions for leaf that I've seen before include "Piece of foliage (to be turned over anew?)" , "Sheet of written material" , "Thin sheet of metal" , "natural process" , "In fall, one dislocated" .)