Burden with wood (6)
I believe the answer is:
lumber
This clue is a double definition.
'burden' is the first definition.
(thesaurus)
'wood' is the second definition.
(thesaurus)
'with' is the link.
(Other definitions for lumber that I've seen before include "articles in storage" , "Wood for building - saddle" , "Burden with an unwanted task" , "Move clumsily - Jack's wood?" , "Unwanted, stored goods" .)