Englishfor English speakers
spotface
noun
—
a shallow circular or cylindrical recess, machined on (for example) a cast part to offer a flat face against which to seat a fastener; a shallow counterbore
spotface
verb
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(transitive) to create or fashion a spotface
diameter
Noun
—
The diameter of a circle is the distance from one point on the circumference of the circle to the point on the opposite side.
The diameter of that circle is 4 inches.