Carry on trade in laminated wood (3)
I believe the answer is:
ply
I believe this is a triple definition!
'carry on' is the first definition.
(ply can mean to work continually at something)
'trade' is the second definition.
(to ply a trade is to work at it)
'in' acts as a link.
'laminated wood' is the third definition.
(thesaurus)
(Other definitions for ply that I've seen before include "A layer to work at diligently." , "Laminate thickness" , "Work steadily as at one's trade" , "Strand, of wool or wood, say" , "'Persist in offering, liquor say (3)'" .)