Definitions
1.NounOne who concentrates.
2.NounA hub.
3.NounAn apparatus for the separation of dry comminuted ore, by exposing it to intermittent puffs of air.
4.NounA frame or ring of wire or hard paper fitting into the cartridge case used in some shotguns, and holding the shot together when discharged, to secure close shooting; also, a device for slightly narrowing the bore at the muzzle for the same purpose.