Old soldier cutting old tree (5)
I believe the answer is:
osier
'tree' is the definition.
(osier is a kind of tree)
'old soldier cutting old' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'cutting' indicates named letters should be taken away.
'soldier' with 'old' removed is 'sier'.
'o'+'sier'='OSIER'
(Other definitions for osier that I've seen before include "Basket-maker's willow" , "one used to get weaving?" , "Wetland willow" , "Tree for basket making" , "Willow with twigs for basket-weaving" .)