A sort of echo hurts nest in tree (5,8)
I believe the answer is:
horse chestnut
'tree' is the definition.
(the horse chestnut is a kind of tree)
'a sort of echo hurts nest' is the wordplay.
'a sort of' indicates an anagram.
'echo'+'hurts'+'nest'='echohurtsnest'
'echohurtsnest' is an anagram of 'HORSE-CHESTNUT'.
'in' acts as a link.
(Other definitions for horse chestnut that I've seen before include "Tree with sticky buds" , "Type of tree" , "whose shade may be seen in park" , "Common British tree" , "Source of timber" .)