screwback noun 11 noun11 •A hook-shapped attachment for an earring that sits behind the earlobe and tightens with a screw. Also, an earring that uses this type of attachment.The clip was a variation of the screwback; today, many persons who cannot wear pierced earrings choose clips as an option. — 2007 •A mechanism for attaching a small item to clothing that operates by a post which goes through the cloth and a small backing plate that screws to the post. Also, the medal, tie pin, button, etc. that uses this type of attachment.The quality of these buttons and charms is best rolled gold and hard enameled in correct colors, the button having either a screwback or a jewelers' catchpin. — 1921 •A type of case for a pocket watch where the mechanism is accessed by a removable back plate that screws onto the back of the case. Also, a watch that has such a case.The watch stolen from Dan Payton had been an Elgin, with a screwback military case. — 2013 •The effect of putting backspin on the cue ball. •A powerful shot that imparts a spin to the ball. •A tightening screw on the back of a hand tool.Ball Bearing armature and spindle thrust, three jaw screwback chuck. — 1931 •The period of screw rotation during injection molding when the plastic can flow into the mold.But in the open (screwback) position, the plastic must progress through a series of labyrinths which produces a more turbulent flow. — 1980 •A type of propeller in which the blades are angled to produce a motion similar to threading a screw. Also, the angle of the blades on such a propeller.The new propeller which was installed in 1982 was a screwback type with a diameter of 5,500 mm. and a mean pitch of 4,290 mm. — 1983 •An industrial digging machine that uses a large screw at the back to drill into the ground.With the help of a screwback shovel, it was excavated to a depth of 13 ft. — 1968 •A masonry abutment on an arch that is wedge-shaped in order to transmit the thrust downward.The main arch abutments are 25 feet wide by 75 feet long and approximately 60 feet deep from the top of the screwback to the bottom of the footings. — 1941 •A half-volley executed by holding the racket loosely and swinging it straight at the ball.
