Definition of down timber in US English:

down timber

noun

North American
  • Fallen trees brought down by wind, storm, or other natural agency.

    ‘dead trees are not cut, nor are dead leaves or down timber removed’
    • ‘This area also had much down timber from a storm 2 years ago.’
    • ‘Material from clearing and grubbing may be processed by such means as chipping of logs, down timber, or brush, for mulching material, or salvaging of logs and down timber for firewood.’