(~s)
1.
A ~ is a round handle on a door or drawer which you use in order to open or close it.
He turned the ~ and pushed against the door.
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2.
A ~ is a round switch on a piece of machinery or equipment.
...the volume ~.
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3.
A ~ of butter is a small amount of it. (mainly BRIT)
Top the steaming hot potatoes with a ~ of butter.
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