sinker

noun

1. That which sinks or descends.
2. One who sinks something.

   “McLachlan's value as a coal miner was enhanced by the specialized skill he learned as a shaft-sinker.”

3. A weight used in fishing to cause the line or net to sink.

   “Hook the sinker onto this loop.”

   “Then the caplin moved off, and five minutes later there was no sound except the splash of the sinkers overside, the flapping of the cod, and the whack of the muckles as the men stunned them.”

4. Any of several high speed pitches that have a downward motion near the plate; a two-seam fastball, a split-finger fastball, or a forkball.

   “His sinkers drew one ground ball after another.”

5. A sinker nail, used for framing in current construction.
6. (slang)A doughnut; a biscuit.

   “Of the fifty cents, ten went for the glassy shoeshine; twenty-five for a boutonniere; ten for coffee and sinkers at the Cockeyed Bakery.”

   “they improvised by opening a barrel of flour and letting each man dump in a quart of water (if he had one) and scoop out a handful of dough to bake into rock-hard sinkers.”

   “"Gonna have to dip them sinkers in coffee to get 'em soft enough to chew," Jason Biggs said, grinning.”

7. In knitting machines, one of the thin plates, blades, or other devices, that depress the loops upon or between the needles.