- a clack valve having two flaps with a common hinge.
- a valve, as the throttle valve in a carburetor, that swings about a central axis across its face.
Origin of butterfly valve
First recorded in 1860–65
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a disc that acts as a valve by turning about a diameter, esp one used as the throttle valve in a carburettor
- a non-return valve consisting of two semicircular plates hinged about a common central spindle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012