From Longman Dictionary of Contemporary Englishsapwoodsap‧wood /ˈsæpwʊd/ noun [uncountable] HBPthe younger outer wood in a tree, that is paler and softer than the wood in the middle
Examples from the Corpus
sapwood• Division of these cells adds new bark to the outer side of the cambium and new sapwood to the inside.• The growth region is a thin band of cells called the cambium, which lies between the bark and the sapwood.• The infection court, said Ketchledge, permits the fungus to enter the cambium layer and the sapwood through the aggregated wounds.• Where most or all of the sapwood is missing, the felling date can not be identified. 