Valve

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late Middle English (denoting a leaf of a folding or double door): from Latin valva .

wiktionary

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From Middle English valve, from Latin valva. Doublet of valva.

etymonline

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valve (n.)

late 14c., "one of the halves of a folding door," from Latin valva (plural valvae) "section of a folding or revolving door," literally "that which turns," related to volvere "to roll," from PIE root *wel- (3) "to turn, revolve." Sense extended 1610s to "membranous fold regulating flow of bodily fluids;" 1650s to "mechanical device that works like an anatomical valve;" and 1660s in zoology to "halves of a hinged shell." Related: Valved.