rough-tree
/ˈrʌftriː/Nautical. Now historical
noun
A roughly shaped but unfinished spar, especially one carried on a ship as a spare mast.
Origin
Early 17th century; earliest use found in Samuel Purchas. Apparently originally a variant of roof-tree, reflecting a pronunciation with/ʌ/ in the first element (apparently resulting from vowel shortening), but reinterpreted from an early date as if from rough + tree.