sleeper
A baulk of timber of rectangular cross-section (about 25 x 15cm), formerly used as a railway sleeper or newly manufactured to a similar specification, and popular for various elements of hard landscaping such as retaining walls, raised beds, path edging, steps etc. Sleepers may also be used as lintels in structures such as barns or garages.
This definition is abridged from A – Z of tree terms: A companion to British arboriculture.
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