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(skwĭnch)
(skwĭnch)n.
A structure, such as a section of vaulting or corbeling, set diagonally across the interior angle between two walls to provide a transition from a square to a polygonal or more nearly circular base on which to construct a dome.
[Alteration of scuncheon, from Middle English sconchon, from Old French escoinson : es-, out of (from Latin ex-; see EX-) + coin, angle, wedge; see COIN.]
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